[page 27↓]

RESULTS

3.1 Morphology

The Cuban species of Pleurothallis reflect the morphologically diverse conditions of the entire genus (Luer 1986b) to a great extent. Morphological descriptions along with figures and data on distribution and ecological preferences are presented in the following. They represent a literal translation of the Spanish manuscript submitted for the Flora de Cuba (Stenzel 2004a).


[page 28↓]

Pleurothallis R. Br. in Aiton, Hortus Kew. ed. 2. 5: 211. 1813.
Type: Pleurothallis ruscifolia (Jacq.) R. Br. (Epidendrum ruscifolium Jacq.).
= Cryptophoranthus Barb. Rodr. Type: Cryptophoranthus fenestratus (Barb. Rodr.) Barb. Rodr. (Pleurothallis fenestrata Barb. Rodr.).

Herbs , epiphytic, lithophytic, or pseudoterrestric. Rhizome very short or elongated. Ramicauls reduced or elongated, simple, superposed (not in Cuba) or branched (not in Cuba), terete to winged or channeled, erect to pendent, partially or entirely covered by scarious sheaths, glabrous or with trichomes, tubular or infundibuliform; with or without an annulus. Leaves usually thick, glabrous or variably papillose or tomentose; margin entire or variably papillose, crenate dentate or serrate. Inflorescence fasciculate or racemose, solitary to numerous, single to multi-flowered, (sub)terminal, erect or pendent, subtended at the base by a sheath or spathe mor or less developed; peduncle very short or elongated with various bracts; anthesis successive, ocalmostonally simultaneous. Floral segments membranous to thickened, glabrous or variably papillose, verrucate, or pubescent; margin entire, variably papillose, ciliate, or cut; apex acute to rounded, truncate to caudate, sometimes thickened or cucullate. Sepals free or variously connate. Petals usually shorter than the sepals, free. Labellum simple, 3- or 5-lobed, base in various foorms hinged to the base or foot of the column. Column stout or slender, straight to arcuate, base often elongated into a foot; clinandrum winged, entire or variably incise. Anther apical to subapical; pollinia 2, 6 (not in Cuba) or 8. Stigma apical (not in Cuba) to ventral, entire to bilobed (not in Cuba). Ovary glabrous or variably verrucate, papillose or pubescent.

Distribution: The same as that of the subtribe. About 1200 species (C. A. Luer, personal communication); 39 in Cuba. Centre of diversity in the (sub)montane rainforests and cloud forests of Central and South America and the Greater Antilles.

Reproduction biology: The same as that of the subtribe. In Cuba there are at least 4 species showing autogamy.

Pleurothallis appendiculata Cogn. in Urban, Symb. Antill. 7: 174. 1912. Holotype: “Santo Domingo [Dominican Republic], prope Constanza”, 1400 m, IV-1910, Türckheim 3233 ex herb. Cogniaux (BR No 843457!). – Fig. 3.

Herbs, caespitose, 3,5-7,5 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls ascending or pendent, distinctly surcate with margins passing into the margins of the leaf, 2-3,5 cm long, 3-articulated below the middle, entirely covered by three scarious sheaths, apically oblique and carinate; without an annulus. Leaves slightly [page 31↓]coriaceous, narrow ovate to elliptic, acute to subacuminate, 1,5-4 x 0,5-1,5 cm, green, glabrous; base cuneate to attenuate; margin entire. Inflorescence a terminal raceme, pendent, up to six per stem, with 2-6 flowers; subtended at the base by a narrow ovate sheath of 0,5 cm in length; peduncle 1-3,5 cm long, with two bracts; axis flexuosus, 0,5-4 cm long. Pedicels 2 mm long, fused up to the middle with the axis; bract membranous, oblique-infundibuliform, acute, carinate, often reddish, up to 0,4 cm long. Flowers resupinate?, anthesis successive. Sepals membranous, slightly thickened along the nerves, green-yellowish with purple stripes, carinate; dorsal sepal basally connate 1 mm with the lateral ones, narrow oblanceolate, acute, 3-veined, 1,3 x 0,2 cm; margin entire to slightly papillose; the lateral ones basally connate 4 mm but adnate almost up to the tip, the base forming a mentum with the ovary, synsepal (broadly) ovate, acute, bifid, 6-veined, 1,1-1,2 x 0,8-0,9 cm; margin entire or slightly papillose. Petals membranous, light reddish, subulate, slightly falcate, acute, 1-veined, 5-6 x 1,2 mm; margin entire to slightly crenulate. Labellum slightly thickened, light reddish to purple, spathulate, trilobate, obtuse, 4-5 x 2,5 mm when expanded, midlobe suborbicular, the lateral ones basally slightly thickened and antrorse, apically broad, membranous, revolute; upper side with two lengthwise calli beyond the middle, apically papillose; base clawed, with two auricles connected by a transverse callus; margin entire below the middle, somewhat sinuate, crenulate or papillose above. Column light reddish, slightly curved inwards, carinate, winged beyond the middle, 4-4,5 mm long; foot 1-1,5 mm long, with a depression elongated; clinandrum winged; margin profoundly dentate. Anther apical; pollinia 2, obtuse-triangular, slender. Stigma ventral. Ovary 2-2,5 mm long, papillose to verruculate. Capsule verrucate. – Fl.: V, Fr.: V-VI.

Distribution: Greater Antilles (except Jamaica). Present in East Cuba: Gr (Sierra Maestra: Buey Above, Barrio Nuevo). Epiphytic; prefers shady and humid conditions in montane rainforests about 1400 m, in vegetation on soils derived from volcanic rock. Very rare, known only from one locality.

Pleurothallis aristata Hook. in Ann. Mag. Nat. Hist., ser. 2, 11: 329. 1839. ≡Specklinia aristata (Hook.) Pridgeon & M. W. Chase in Lindleyana 16: 256. 2001. Lectotype (designated here): “Pleurothallis aristata” [based on material from Demerara, Guyana, cultivated in Liverpool by Parker] in Ann. Mag. Nat. Hist., ser. 2, 11: t. 15. 1839. – Fig. 4.

= Pleurothallis urbaniana Rchb. f. in Ber. Deutsch. Bot. Ges. 3: 279. 1885. Holotype: “Puerto Rico, Maricao, Indiera Fría”, 3-XII-1884, Sintenis, Plantae portoricenses No. 503 (W ex herb. Reichenbach Orch. No. 25575!).

Herbs, caespitose, 1,5-3 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls ascending, 1-3 mm long, 2-articulated, entirely covered by two membranous sheaths; annulus present. Leaves slightly thickened, narrow elliptic to oblanceolate, acute to subobtuse, tridentate with the middle tooth being elongated, 1,4-2,7 x 0,4-0,5 cm, green, glabrous; base narrow attenuate; margin entire. Inflorescence a terminal raceme, ascending, two per stem, 2-6 flowers; subtended at the base by a lanceolate and conduplicate sheath of 0,5-1 mm in length; peduncle 2,5-4,5 cm long, with two bracts; axis 0,5-1,5 cm long. Pedicels up to 9 mm long, fused 0,7 mm with the axis; bract membranous, tubular to infundibuliform, 1,4-1,7 mm long. Flowers with successive anthesis. Sepals membranous, greenish with purple stripes; margin papillose; dorsal sepal free, lanceolate, caudate, 3-veined, 6,5 x 1,5 mm; the lateral ones connate basally 1 mm, lanceolate, carinate, caudate, 2-veined, 6,5 x 1,3 mm. Petals membranous, hyaline with a purple nerve, oblique spathulate, acute, 1-veined, 3 x 1 mm; margin profoundly fimbriate to lacerate. Labellum slightly thickened, purple, oblong, trilobate, obtuse to retuse, 2,3 x 1,3 mm when expanded, midlobe suborbicular, papillose to pilose, the lateral ones denticulate, antrorse; upper side with a central lengthwise depression on the lower half, apically papillose; lower side distinctly carinate; base truncate; margin papillose, verrucate, revolute. Column whitish, slightly curved inwards, 2 mm long; foot 0,5 mm long, with two orbicular calli; clinandrum slightly winged, margin serrate. Anther apical; pollinia 2, pyriform, sculpture punctate. Stigma ventral. Ovary 1-1,5 mm long, [page 32↓]glabrous. Capsule 6 mm long, glabrous and ribbed. – Fl.: V-VII, Fr.: V-VIII.

Distribution: Tropical America and Antilles. Present in east Cuba: SC (Sierra Maestra: falda sur of the Pico Turquino). Epiphytic; prefers shady and humid conditions in cloud or montane rainforests about 1800 m. Known from a single collection.

Fig. 3: Pleurothallis appendiculata Cogn.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip. 6 – Lip, ovary and column in natural position.

Fig. 4: Pleurothallis aristata Hooker.

1 – Plant. 2 – Inflorecence, upper part. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Pleurothallis bissei Luer in Lindleyana 14: 108. 1999. Holotype: “Cuba, Holguín, Mayarí, lower Sierra de Nipe, Loma la Mensura”, 31-X-1977, Bisse & al. (HAJB!). – .

Herbs, subrepent, 2,5-8,5 cm high (excluding the inflorescence).stems with tubular sheaths which are densely covered with scale-like, erect, brownish red hairs. Rhizome slightly elongated, separating the ramicauls by 2-4 mm. Ramicauls erect or ascending, 1-4,5 cm long, 3-articulated; without an annulus. Leaves coriaceous, narrow elliptic, acute to subobtuse, often tridentate, 1,4-4 x 0,4-0,7 cm, yellowish green and uneven on the upper side, green and glabrous on the lower side; base cuneate; margin finely serrate. Inflorescence a terminal raceme, ascending, two per stem, with 2-3 flowers, subtended at the base by an ovate and conduplicate sheath of 1-2 mm in length; peduncle 0,3-0,4 cm long, with two bracts; axis 0,4-1 cm long. Pedicels 1-1,5 mm long, fused below the middle with the axis; bract membranous, tubular, 1-1,3 mm long. Floral segments membranous, 3-veined, acute; anthesis successive. Sepals whitish, with the nerves reddish; margin slightly asper; dorsal sepal basally connate 1 mm with the lateral ones, (narrow) elliptic, 6,9-7,2 x 2,2-2,4 mm; the lateral ones basally connate 1 mm but adnate up to beyond the middle, the base forming a mentum with the ovary, narrow elliptic-ovate, 6,9-7,2 x 2-2,1 mm. Petals whitish, oblanceolate, 4,5 x 1,7 mm; margin apically serrulate. Labellum slightly thickened to membranous, reddish to deep red, narrow oblong, rounded, 4-4,2 x 1,1-1,2 mm when expanded; upper side with two lengthwise calli above the middle; base truncate; margin antrorse below the middle, crenulate above. Column white, slender, slightly curved inwards, 3 mm long; foot up to 1 mm long; clinandrum slightly winged, margin entire. Anther apical; pollinia 2, lentiform, sculpture granulate. Stigma ventral. Ovary 1 mm long, glabrous. Capsule 5 mm long, glabrous with prominent and verrucate ribs. – Fl.: XI-II, Fr.: XI-IV.


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Distribution: Endemic in eastern Cuba: Ho. Lithophytic; prefers open places like the banks of rivulets, in gallery forests from 700 to 900 m, on serpentine rock. Rare.

Ecology: Plants growing on river banks stand temporal inundations during the rainy season.

Fig. 5: Pleurothallis bissei Luer

1 – Plant. 2 – Scale. 3 – Flower. 4+5 – Sepals. 6 – Petal. 7 – Lip. 8 – Lip, ovary and column in natural position.

Fig. 6: Pleurothallis brighamii S. Wats.

1 – Plant. 2 –  Flower. 3+4 – Sepals. 5 – Petal. 6+7 – Lip. 8 – Base of lip, ovary and column in natural position.

Pleurothallis brighamii S. Watson in Proc. Amer. Acad. Arts 23: 285. 1888. ≡Specklinia brighamii (S. Watson) Pridgeon & M. W. Chase in Lindleyana 16: 256. 2001. Holotype: “Guatemala: eastern portion of Verapaz and Chiquimula, [flowering] Cambridge - Aug. 1887” [Chocón], VIII-1887, Watson (AMES No. 72461 [photo!]). – .

Herbs, caespitose, 2-3,5 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, straight, 0,9-2,2 mm long, 3-articulated, entirely covered by three scarious and tubular sheaths; annulus present. Leaves slightly thickened and somewhat coriaceous, spathulate, acute or obtuse, slightly tridentate, 1,5-3,3 x 0,3-0,6 cm, green, glabrous; base narrow attenuate; margin entire. Inflorescence a terminal congested raceme, solitary, few-flowered; peduncle 2,4-3,7 cm long, with two or three bracts; axis 1-3 mm long. Pedicels 2,5-3 mm long, free; bract membranous, tubular, acuminate, up to 2 mm long. Flowers with a successive anthesis. Sepals y petals membranous to slightly thickened, yellow with red stripes, carinate, acute; margin entire; dorsal sepal free, oblong-elliptic to narrow obovate, 3-veined, 5,8-6,2 x 2-2,3 mm; the lateral ones connate to 2/3, the base forming a mentum with the ovary, synsepal elliptic, bifid, 6-veined, 5,9-6,2 x 3-3,4 mm; petals oblique, spathulate, 2-veined, 2,5 x 1,3 mm. Labellum slightly thickened, yellow with a red margin, oblong, recurved, rounded, 2,8-3 x 1 mm when expanded; upper side with two lengthwise calli above the middle, apically minutely papillose; base subcordate; margin with two straight auricles in the middle, tip papillose. Column stout, yellowish with red margin, 1,5 mm long; foot ± 1 mm long, with a suborbicular depression and two acute auricles close to the base; clinandrum slightly winged, bidentate. Anther apical; pollinia 2, broadly obovate, sculpture punctate to granulate. Stigma ventral. Ovary ± 1 mm long, glabrous. Capsule 6-8 mm long, ribbed. – [page 34↓]Fl.: II-VIII, Fr.: II-X.

Distribution: Central America from México to Costa Rica, Greater Antilles (except Puerto Rico). Present in West Cuba: PR (Sierra of the Rosario: Río Taco Taco); Central Cuba: Santi-Spirit. Mts., Sierra Caballete; East Cuba: Ho, SC, Gu. Epiphytic or lithophytic; prefers humid and shady places generally close to water in gallery forests, montane rainforests, cloud forests and secondary forests (cupeyales) from 350 to 700 m, in vegetation on soils derived from limestone or serpentine rock. Rare.

Ecology: Frequently in association with Pleurothallis corniculata.

Fig. 7: Pleurothallis caymanensis C.D.Adams.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 8: Pleurothallis corniculata (Sw.) Lindl.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip. 7 – Base of lip, ovary and column in natural position.

Pleurothallis caymanensis C. D. Adams in Orquideologia 6: 146. 1971. Holotype: “Grand Cayman: along road to North Side, 0.4 mile [650 m] SE of Old Man Village, rocky limestone woodland”, 9-VI-1967, Proctor 27983 (IJ!). – .

Herbs, subcaespitose, 1-2 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls up to 6 mm long, 3-articulated below the middle, entirely covered by two scarious sheaths; without an annulus. Leaves thickened and rigid, ovate to broadly elliptic or suborbicular, conduplicate, acute, acuminate or apiculate, 6-12(-14) x 4-7 mm, yellowish green and verrucate on the upper side, green and rough on the lower side; base cuneate; margin crenulate to erose. Inflorescence a terminal raceme, ascending, two per stem, (1-)2-3 flowers, subtended at the base by a lanceolate sheath of 1 mm in length; peduncle 1-2,5 cm long, with 2-4 bracts; axis 0,5-1 cm long. Pedicels 1-1,2 mm long, free; bract membranous, tubular or slightly infundibuliform, loosely verrucate, basally reddish, 1 mm long. Flowers with a successive anthesis. Sepals membranous, slightly thickened along the nerves, greenish yellow with purple stripes, carinate; dorsal sepal free, lanceolate, acute, 3-veined, 5-5,7 x 0,9-1,1 mm; margin entire; the lateral ones connate basally but adnate up to the tip, the base forming a mentum with the ovary, synsepal lanceolate, acute, bifid, 6-veined, 5-5,3 x 2-2,3 mm; margin entire. Petals membranous, whitish with a reddish nerve and a deep red dot at the apex, spathulate, rounded to emarginate, 1-veined, carinate, 2 x 1 mm; margin irregularily serrate. [page 35↓] Labellum slightly thickened, reddish and deep purple, oblong to spathulate, rounded, 2,7 x 1 mm when expanded; upper side with two lengthwise, verrucate calli; base attenuate, biauriculate; margin entire or crenulate and with two purple lobes. Column light reddish and apically purple, curved inwards, 1,5 mm long; foot 1 mm long, with an elongated depression; clinandrum winged and serrate. Anther subapical; pollinia 2?. Stigma ventral. Ovary 1 mm long, rough. Capsule 5-6 mm long, verrucate on the ribs. – Fl.: III-VII, Fr.: III-VIII.

Distribution: Greater Antilles (Cuba and Grand Cayman). Present in West Cuba: PR (Guanahacabibes: Barra la Sorda). Epiphytic; prefers humid places in semideciduous forests at low elevations, generally in vegetation on limestone. Known from one locality.

Pleurothallis corniculata (Sw.) Lindl. in Bot. Reg. 28: misc. 83, no. 110. 1842 (excl. syn.). ≡Epidendrum corniculatum Sw., Prodr.: 123. 1788. ≡Dendrobium corniculatum (Sw.) Sw. in Nova Acta Regiae Soc. Sci. Upsal. 6: 83. 1799. ≡Cymbidium corniculatum (Sw.) Spreng., Syst. Veg. 3: 722. 1826. Lectotype (Fawcett & Rendle 1910: 61, specified here): “Epidendrum corniculatum Swartz, Jamaica”, Swartz (BM!; isolectotypes?: S ex herb. Alstroemer [foto!], W ex herb. Reichenbach Orch. No. 26609!). – Fig. 8.

=Pleurothallis nubigena Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 326. 1858 [as “rubigena”]. Lectotype (designated here): “in Cuba Orientali, 1856-7” [blue label], Wright 657 (K-L!; isolectotypes?: G ex herb. Barbey-Boissier!, K!).

–“Pleurothallis hymenantha” sensu Lindley (1860: 219) (non Pleurothallis hymenantha Lindl.).

Herbs, caespitose, 2-5 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, straight, 3-6 mm long, 4-articulated, entirely covered by 4 scarious, tubular or slightly conduplicate sheaths; annulus present. Leaves slightly coriaceous, elliptic to oblanceolate or spathulate, acute to obtuse, tridentate, 1,7-4,5 x 0,5-0,7 cm, green, glabrous; base attenuate; margin entire. Inflorescence terminal, solitary, single flowered, straight, subtended at the base by an ovate and acute sheath of 1-1,7 mm in length; peduncle 2,5-3,5 cm long, with one bract. Pedicels 0,6-1 cm long; bract membranous, conduplicate, short apiculate, 1,8-2,1 mm long. Sepals membranous to slightly thickened, yellowish green, carinate, slightly papillose on the outside along the nerves; dorsal sepal basally connate with the lateral ones, narrow elliptic, acute, 3-veined, 5-6 x 1,6-1,8 mm; margin entire; the lateral ones connate only basally but adnate up to the tip, the base forming a mentum with the ovary, synsepal narrow ovate, acute, 6-veined, 4,5-5,5 x 2,2-2,6 mm; margin glabrous. Petals membranous, whitish, elliptic, oblique in the upper part, acute, 3-veined, 2,5-2,8 x 0,7-0,9 mm; margin entire. Labellum slightly thickened, whitish, narrow ovate to lanceolate, rounded, 2,5 x 1 mm when expanded; upper side with two lengthwise, papillose calli above the middle, apically papillose; lower side papillose along the nerves; base truncate, short clawed; margin entire, antrorse below the middle, ciliate or papillose above. Column whitish, slightly curved inwards, 1,6 mm long; foot 0,6 mm long; clinandrum slightly winged, bidentate. Anther apical; pollinia 2, generally amorph with a reduced sculpture, or rarely, in flowers open (xenogamous), oblong to obovate with a granular sculpture. Stigma ventral. Ovary 1 mm long, glabrous or verrucate along the ribs. Capsule 6,5-7 mm long, with slightly verrucate ribs. – Fl.: I-XII, Fr.: I-XII.

Distribution: Central America from Belize to Costa Rica (Pánama?), Greater Antilles (Cuba, Jamaica), Hispaniola (Dod 1984b: 107). Present in West Cuba: PR; Central Cuba: Ci (Sierra de Escambray), SS; East Cuba: Ho, Gr, SC, Gu. Epiphytic or lithophytic; prefers humid and shady or open conditions in vegetation of the mogotes, montane rainforests, gallery forests, and in degraded forms of these forest types like in secondary forests (cupeyales), from 300 to 800 m, usually associated with the vegetation on limestone. Common.

Ecology: Frequently in association with Pleurothallis sertularioides, Pleurothallis [page 36↓] tribuloides and Pleurothallis wilsonii.

Reproduction biology: Some characteristics, like the generally closed flowers (Wright in herb. and pers. observ.), and the amorphous pollinia with a reduced and fragile exinous layer, suggest autogamy and probably cleistogamy in most of the Antillean plants.

Fig. 9: Pleurothallis denticulata Cogn.

1 – Plant. 2 – Pedicel and bract. 3 – Flower. 4+5 – Sepals. 6 – Petal. 7 – Lip. 8 – Lip, ovary and column in natural position.

Fig. 10: Pleurothallis domingensis Cogn.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position. 7 –  Fruit with persistent flower.

Pleurothallis denticulata Cogn. in Urban, Symb. Antill. 6: 425. 1909. Lectotype (designated here): “Cuba oriental, prís de Monteverde”, [Loma del Gato, according to Cogniaux (1909)], Wright 657 p.p. ex herb. Cogniaux (BR No. 843468!). – .
=Pleurothallis parvula Ames & C. Schweinf. in Sched. Orchid. 8: 30. 1925. Holotype: “Cuba: High Maestra” [Pico Turquino], VII-1922, León 10790 (NY No. 59805 [photo!]; isotype: HAC No. 7209!).
=Pleurothallis platyglottis L. O. Williams in Ceiba 1: 228. 1951. Holotype: “Haiti: Guimbi Galata, Mornes des Commissaires”, 1800 m, 21-VI-1942, Holdridge 1287 (AMES [n.v.]).

Herbs, caespitose, 2,5-6 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls straight, ascending or pendent, 1-2,5 cm long, basally 2-articulated, to 2/3 covered by two scarious, conduplicate and carinate sheaths; without an annulus. Leaves coriaceous, ovate to narrow elliptic, distinctly carinate, acute, tridentate, 1,5-3,5 x 0,7-1,3 cm, green, slightly rough on the upper side, glabrous on the lower side; base short attenuate; margin denticulate, revolute. Inflorescence a terminal raceme, pendent, (1-)2-5(-10) per stem, with 2-10 flowers, subtended at the base by an ovate and acute sheath of 1,2-2,5 mm in length; peduncle 1-3,5 cm long, with one bract; axis 2-5,5 cm long. Pedicels 2,5-3,1 mm long, fused beyond the middle with the axis; bract membranous, conduplicate, acuminate, 2,5-3,2 mm long. Flowers with a successive anthesis. Sepals and petals membranous, slightly thickened along the nerves, greenish or yellowish with purple nerves, carinate, acute; margin minutely denticulate; dorsal sepal free, linear lanceolate to narrow elliptic, slightly reflexed, 3-veined, 9-10 x 2-2,1 mm; the lateral ones adnate almost up to the tip, the base forming a mentum with the ovary, synsepal ovate, [page 37↓]bifid, 6-veined, 9-9,6 x 4-4,2 mm; minutely denticulate on the nerves on the outside. Petals membranous, hyaline, light reddish, (narrow) lanceolate, 1-veined, 4-5 x 0,7 mm. Labellum thickened, purple with a dark purple margin, obovate to spathulate, slightly lobed, rounded, 2,5-3 x 1,5-1,7 mm when expanded; upper side with two lengthwise calli bordering a central depression; base clawed, biauriculate; margin denticulate and antrorse in the middle, crenulate and revolute in the upper part. Column light reddish, clawed, slightly curved inwards, 2,5-3 mm long; foot 0,6 mm long; clinandrum distinctly winged, denticulate. Anther apical; pollinia 2, obtusely triangular, sculpture punctate. Stigma ventral. Ovary 1,3 mm long, minutely verrrucate on the ribs. Capsule 6 mm long, with verrucate ribs. – Fl.: V-XI, Fr.: V-XII.

Distribution: Greater Antilles (Cuba, Hispaniola). Present in East Cuba: Gr (Sierra Maestra: Pico Turquino; Victorino: Loma El Gigante), SC (Gran Piedra). Epiphytic; prefers humid and shady places close to the ground in montane rainforests, usually in Barril forest (Cyrilla racemiflora) from 900 to 1500 m. Common.

Variability: This species is variable regarding form and margin of the leaf and floral segments. The color ranges from greenish and slightly, mottled with purple to entirely purple flowers with only the base being somewhat greenish.

Pleurothallis domingensis Cogn. in Urban, Symb. Antill. 6: 402. 1909. ≡Stelis antillensis Pridgeon & M. W. Chase in Lindleyana 17: 98. 2002. Lectotype (Luer 1998a: 20): “Santo Domingo [Dominican Republic]: Valle Nuevo”, 1900 msm, 29-V-1887, Eggers 2176 (BR [ex herb. Cogniaux] No. 843471!; isolectotype: K!). – Fig. 10.

– “Pleurothallis velaticaulis” sensu Lindley (1860: 219), Alain (1958: 41, 43), Adams (1972: 108) et auct. fl. cub. (non Pleurothallis velaticaulis Rchb. f.).

– “Pleurothallis crassipes” sensu Cogniaux (1909: 400) (non Pleurothallis crassipes Lindl.).

Herbs, caespitose, 10-30(-40) cm high (excluding the inflorescence). Rhizome reduced. Ramicauls ascending, 6-24 cm long, 1-articulated below the middle, partially covered by three tubular sheaths, carinate; annulus present. Leaves coriaceous, (broadly) elliptic, obtuse to retuse, 4-16 x 1,5-3,5 cm, green, glabrous; base attenuate; margin entire. Inflorescence a terminal raceme, erect, 1-4 per stem, multi-flowered, subtended at the base by a narrow ovate and acute sheath of 0,5-0,8 cm in length; peduncle 0,5-1,5 cm long, with two or three bracts; axis 2,5-11,5 cm long. Pedicels 0,5-1 mm long, free; bract membranous, infundibuliform, acute, 2-4 mm long. Flowers with a simultaneous anthesis. Sepals membranous, greenish to yellowish, rarely with a tint of red, carinate; margin entire or crenulate, involute; dorsal sepal free, (narrow) ovate, acute, 3-veined, 2-4,5 x 1,1-1,3 mm; the lateral ones adnate up to the middle or close to of the tip, the base forming a mentum with the ovary, synsepal ovate, bifid, 6-veined, 2-4 x 1,5-3,4 mm. Petals membranous, hyaline, narrow spathulate or oblanceolate, obtuse to rounded, 1-veined, 1,5-2 x 0,5 mm; margin entire. Labellum slightly thickened, whitish, ovate to elliptic, trilobate, obtuse, 1,6-1,8 x 1,2-1,3 mm when expanded, midlobe broadly ovate and patent, the lateral ones antrorse; upper side basally with a circular cavity and a callus in the upper part; base cuneate to obtuse; margin entire to crenulate. Column white, straight, 1,3 mm long; foot 0,5 mm long, thickened; clinandrum slightly winged, denticulate. Anther apical; pollinia 2, suborbicular to triangular or amorphous, sculpture octomeriform (s. Stenzel 2000). Stigma ventral. Ovary 1,5 mm long, surcate. Capsule 6 mm long, glabrous, ribbed. – Fl.: VIII-XII, Fr.: VIII-I.

Distribution: Greater Antilles and Guadalupe. Present in East Cuba: Ho (Sierra del Cristal: Pico Cristal), Gr, SC, Gu. Epiphytic or Lithophytic; prefers humid and shady places in montane rainforests and cloud forests from 900 to 1500 m. Rare.

Reproduction biology: Populations with smaller flowers seem to be autogamous or even cleistogamous. They show fragile and amorphous pollinia. Though open flowers were never observed, plants develop a complete fruit set.


[page 38↓]

Variability: The size of the flowers is quite variable, which may reflect the type of the repoduction biology.

Fig. 11: Pleurothallis ekmanii Schltr.

1+3 – Plant. 2 – Leaf, cross section. 4 – Flower. 5+6 – Sepals. 7 – Petal. 8 – Lip. 9 – Lip, ovary and column in natural position.

Fig. 12: Pleurothallis ekmanii Schltr.

1 – Plant. 2 – Leaf, cross section. 3+4 – Sepals. 5 – Petal.

Pleurothallis ekmanii Schltr. in Urban, Symb. Antill. 9: 61. 1923. Holotype: “Cuba: Oriente, Sierra del Cristal, in caumine montis, locis rupestr.”, 1325 msm, 08-III-1916, Ekman 6831 (S!). – ,

=Pleurothallis bovilabia C. Schweinf. in Amer. Orchid Soc. Bull. 15: 234. 1946. Holotype: “Cuba, Oriente, Moa, Monte de la Breña, banks of a rivulet, on chromium rocks”, León & al. 22586 (AMES No. 62496!).

Herbs, caespitose or subcaespitose, 0,7-1,8 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls up to 0,5 mm long, basally 2-articulated, entirely covered by two scarious, infundibuliform, conduplicate and acute sheaths; without an annulus. Leaves coriaceous, obovate to spathulate or (broadly) elliptic, plane or folded, obtuse, acute or subacuminate, tridentate, 0,6-1,7 x 0,3-0,5 cm, green to greyish green on the upper side, green on the lower side; base narrow or short attenuate; margin denticulate in the upper part (sometimes entire). Inflorescence apparently basal, a pendent or erect, solitary, 2-few-flowered raceme; peduncle 1,3-7 cm long, with two or three bracts; axis glabrous or minutely verrrucate, 0,7-5 cm long. Pedicels 0,6-1,2 mm long, fused below the middle with the axis; bract membranous, tubular, acute, slightly conduplicate, 0,8-1,5 mm long. Flowers with a successive anthesis. Sepals slightly thickened, (greenish) yellow and with a tint of red, convex, 3-veined, apically with minutely verrucate keels; margin entire or minutely denticulate in the upper part; dorsal sepal free, elliptic or oblong, obtuse, short acuminate, 3,2-4,5(-5,9) x 1,8-2,1 mm; the lateral ones free but often adnate to the tip, (narrow) elliptic to oblong, slightly falcate, obtuse, short acuminate or apiculate, 3,5-5(-6) x 1,8-2 mm. Petals membranous, yellowish to reddish, spathulate, acute to obtuse, 1-veined, 2,8-3,1 x 0,9-1 mm; margin apically denticulate or obtuse-serrate. Labellum membranous, partially thickened, whitish and with red dark dots, slightly panduriform, trilobate, rounded and short apiculate, 3 x 3,2 mm when expanded, midlobe suborbicular with a circular disc, broadly clawed, the lateral ones elongated, [page 39↓]antrorse; upper side with two calli bordering a central depression; base truncate, with two obtuse, antrorse, dark red lobes; margin entire. Column whitish, elongated, curved inwards, 2,2 mm long; foot reduced; clinandrum winged. Anther apical; pollinia 8, claviform, sculpture fossulate. Stigma ventral. Ovary 1 mm long, glabrous. Capsule 5-6 mm long. – Fl.: II-VII, Fr.: II-VIII.

Distribution: Endemic in East Cuba: Ho, Gu (Yateras: Pico Galán). Epiphytic or lithophytic; prefers humid places, like the banks of rivulets or foggy mountain crests, in charrascales or gallery forests from 600 to 900 m, exclusively in vegetation on soils derived from serpentine. Rare.

Variability: This species is highly variable in its morphology. Fig. 11 and Fig. 12 show extremes in foliar and floral morphology. Observations in the field suggest the existence of various forms. Most distinct differences were found between epiphytic (Fig. 11) and lithophytic or pseudoterrestric populations (Fig. 12). Lithophytic plants show a very compact habit, erect inflorescences and bigger flowers. Because of these differences, Schweinfurth (1946) published a collection of terrestric plants as Pleurothallis bovilabia C. Schweinf. However, there are intermediate forms and some of the presumed “distinct” characteristics can be found even within the same population.

Pleurothallis excentrica (Luer) Luer in Rev. Soc. Boliviana Bot. 3(1-2): 50. 2001. ≡Octomeria excentrica Luer in Lindleyana 14: 106. 1999. Holotype: “Cuba, Moa, Río Cayoguán”, VII-1949, Alain & al. 896 (AMES [n.v.]; isotype: Herb. Ch. F. Barker No. 15598 [n.v.]). – Fig. 13.

Herbs, subrepent. Rhizome elongated, separating the ramicauls by 1-2 mm, covered by various scarious and infundibuliform sheaths. Ramicauls subreduced, entirely covered by two scarious, infundibuliform, acute sheath; without an annulus. Leaves thickened, subprostrate, oblanceolate, obtuse to retuse, tridentate, 0,8-1,5(-2) x 0,2-0,4 cm, green to greyish green or purplish green, rough on the upper side, dark green and rough on the lower side; base cuneate; margin entire. Inflorescence apparently basal, a solitary racime with 1(-2) flowers, subtended at the base by a scarious sheath of 4 mm in length, fused with the peduncle; peduncle erect, up to 4 mm long, with two bracts; axis reduced, barely 1 mm long. Pedicels 0,5 mm long, almost entirely fused with the axis; bract membranous, infundibuliform, <1 mm long. Sepals thickened, brownish purple, whitish towards the base, connate at the very base, narrow ovate, acute or slightly acuminate, 3-veined, convex, carinate; margin entire; dorsal sepal 4,8-5,2 x 2,5-3 mm; the lateral ones, 4,8-5,2 x 2-2,4 mm. Petals somewhat thickened, purple, oblanceolate, slightly panduriformes, acute, subacuminate, 1-veined, 4,5 x 1,5-1,8 mm; margin minutely crenulate above. Labellum thickened, dark purple and whitish, ovate, acute or subobtuse, 4-4,2 x 2,2-2,5 mm when expanded; upper side with a basal circular depression, apically with minute calli and teeth; base truncate; margin below the middle crenulate, in the middle with two antrorse teeth, towards the the tip irregularily denticulate. Column whitish with purple, slightly curved inwards and apically winged, 2,5 mm long; foot 0,5 mm long; clinandrum winged and crenulate. Anther subapical; pollinia 8, pyriform to claviform, sculpture psilate. Stigma ventral. Ovary 2 mm long, glabrous. Capsule ribbed. – Fl.: IV-VI, Fr.: V-VII.

Distribution: Endemic in East Cuba: Ho, SC (Sierra del Cristal: Río Lebisa), Gu. Epiphytic; prefers humid and shady to open conditions, along waterways or foggy mountain crests in gallery forests or montane rainforests from 300 to 800 m, restricted to the vegetation on serpentine rock. Rare.


[page 40↓]

Fig. 13: Pleurothallis excentrica (Luer) Luer.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 14: Pleurothallisflabelliformis’ H. Stenzel

1  – Plant. 2 –  Flower. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Pleurothallis flabelliformis H. Stenzel, comb. nov. et nom. nov. ≡Octomeria prostrata H. Stenzel in Lindleyana 16: 26. 2001. Holotype: “Cuba, Holguín, Sierra del Cristal, cabezadas del Río Lebisa, 500 m río abajo desde el campamiento base del trillo al Pico, 20°31'39''N, 75°29'10''Oe”, 650-700 m, 29-V-1998, Stenzel & Matos 516 (HAJB!; isotype: JE!). – .

Herbs, caespitose to subrepent, 2-4 cm high. Rhizome subreduced. Ramicauls 0,5-1,5 mm long, 2-articulated, entirely covered by two scarious and tubular sheaths; without an annulus. Leaves slightly coriaceous, spathulate, obtuse to retuse or emarginate, 1-3,5 x 0,7-1,5 cm, green and plane on the upper side, green and purple and convex on the lower side; base narrow attenuate or cuneate-attenuate; margin minutely crenulate. Inflorescence apparently basal, two per stem, a 2-3-flowered receme, subtended at the base by a scarious, acute sheath, of 3 mm in length; peduncle straight, up to 3 mm long, with various bracts; axis 3 mm long. Pedicels 0,5 mm long, fused partially with the axis; bract membranous, slightly conduplicate and acute, 2 mm long. Flowers resupinate or not, anthesis successive. Sepals thickened, whitish with purple towards the tip, narrow ovate to lanceolate, acute, 3-veined, distinctly carinate; margin entire; dorsal sepal free, 5,8-6,2 x 2-2,4 mm; the lateral ones connate at the very base, slightly falcate, 5,8-6,2 x 2-2,4 mm. Petals membranous, whitish, mottled with purple, spathulate, acuminate, 1-veined, 5 x 1,7 mm; margin minutely crenulate or denticulate above. Labellumthickened, whitish and purple, panduriform, subacute, 3,5 x 1,3-1,5 mm when expanded; upper side with a basal elongated depression covered by transverse calli, by two verrucate calli in the middle and warts in the upper part; base truncate, subcordate; margin biauriculate and antrorse below the middle, crenulate in the upper part. Column whitish or light reddish, elongated, slightly curved inwards, apically winged, 2-2,5 mm long; foot 0,5 mm long; clinandrum winged. Anther subapical; pollinia 8, pyriform to claviform, sculpture psilate. Stigma ventral. Ovary 1-1,5 mm long, glabrous. Capsule slightly ribbed. – Fl.: V-VII, Fr.: V-VIII.

Distribution: Endemic in East Cuba: Ho, SC (Sierra del Cristal: Río Lebisa), Gu [page 41↓](Yateras: Palenque, Loma Bernardo[?]; Maisí). Epiphytic; prefers humid and shady to open conditions like the banks of waterways in gallery forests or, rarely, montane rainforests from 300 to 800 m, restricted to the vegetation on serpentine rock. Rare.

Pleurothallis gelida Lindl. in Bot. Reg. 27: misc. 91, no. 186. 1841. ≡Stelis gelida (Lindl.) Pridgeon & M. W. Chase in Lindleyana 16: 263. 2001. Holotype: “Loddiges, Nov. 1841” [Jamaica], Loddiges (K-L!). – Fig. 15.

=Pleurothallis univaginata Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 326. 1858. Lectotype (Luer 2000: 69, specified here): “in Cuba Orientali, 1856-7” [Filantropia or Loma del Gato] [blue label], Wright 656 p.p. (K-L!; isolectotypes?: G!, K!).

Herbs, caespitose, 20-55 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls ascending, 12-30 cm long, 2-articulated, partially covered by three tubular sheaths, carinate; annulus present. Leaves coriaceous, obliquely lanceolate to narrow elliptic or oblong, often conduplicate, acute to obtuse, 8-25 x 4-8 cm, green, glabrous; base attenuate; margin entire. Inflorescence a terminal raceme, erect or ascending, 1-4 per stem, multi-flowered, subtended at the base by a oblong and falcate sheath of 2-3 cm in length; peduncle glabrous, 0,5-1,5 cm long, with two bracts; axis glabrous, 11-17 cm long. Pedicels 3-4 mm long, basally fused by 1 mm with the axis; bract membranous, tubular, 2-3 mm long. Flowers resupinate, with an simultaneous? anthesis. Sepals membranous, yellowish, 3-veined, basally connate, acute; margin apically crenulate; dorsal sepal ovate, 4,9-5,1 x 2,7-2,8 mm; the lateral ones forming a mentum with the tip of the ovary, oblique-ovate, 4,9-5,1 x 2,5 mm, the upper part internally papillose. Petals membranous, whitish, obovate, rounded or emarginate, 3-veined, 3 x 2 mm; margin apical slightly erose. Labellum membranous, partially thickened, whitish, oblong to narrow obovate, slightly trilobate, recurved, rounded, 2,1 x 1 mm when expanded, midlobe suborbicular, the lateral ones less distinct, antrorse; upper side papillose below the middle and with two elongated calli beyond the middle; base short clawed; margin apically slightly crenulate. Column whitish, short, slightly curved inwards, up to 2 mm long; foot 0,8-1 mm long; clinandrum somewhat winged and denticulate. Anther apical; pollinia 2, broadly ovate, sculpture granulate to subgemmate. Stigma ventral. Ovary 1,3 mm long, glabrous. Capsule 5-11 mm long, obovate, glabrous, ribbed. – Fl.: X-XII, Fr.: X-I.

Distribution: Subtropical and Tropical America from Flórida to South America (Brasil, Bolivia), Greater Antilles. Present in West Cuba: PR (Pan Guajaibón; Sierra del Rosario: Lomas Rangel); Central Cuba: Ci (Sierra de Escambray: Pico San Juan), VC (Escambray: Pico El Tuerto; lomas in the alrededores Manantiales), SS (Trinidad: Pico Potrerillo); East Cuba: Gr, Ho, SC, Gu. Epiphytic or Lithophytic; prefers open to shady places like rocks or tree canopies in vegetation of the mogotes, gallery forests, evergreen mesophyllous forests, montane rainforests and secondary forests (cupeyales). Scattered.

Pleurothallis gemina H. Stenzel in Lindleyana 16: 28. 2001. Holotype: “Cuba, Holguín, Sierra de Nipe, La Mensura, ladera norte, 20°29'30N 75°48'21Oe, bosque latifolia”, 850 msm, 24-IV-1998, Stenzel & Matos 452 (Holotype HAJB!; isotype: JE!). – Fig. 16.

Herbs, subrepent, 5-10 mm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, ascending, 1-1,5 mm long, 3-articulated, entirely covered by three hyaline sheaths; annulus present. Leaves slightly thickened, broadly oblong to obovate or spathulate, obtuse to rounded, minutely tridentate, 4-8 x 2-4,5 mm, green, covered with small warts on the upper side, glabrous on the lower side; base attenuate; margin entire. Inflorescence a terminal raceme, erect to ascending, solitary, generally with two simultaneously open flowers; peduncle glabrous, 2-4 mm long, with two bracts; axis glabrous, 2 mm long. Pedicels up to 2 mm long, free; bract membranous, tubular or infundibuliform, up to 1 mm long. Flowers resupinate, with simultaneous anthesis. Sepals membranous to slightly thickened, whitish, 3-veined, acute, tips thickened and greenish; margin entire; dorsal sepal free, narrow ovate to lanceolate, 3-3,3 x 1-1,3 mm; the lateral ones connate basally, forming a mentum with the tip of the ovary, lanceolate, slightly carinate on the outside, 3-3,3 x 1 mm. Petals membranous, white, narrow oblong to [page 42↓]spathulate, obtuse, 1-veined, 1,7 x 0,5 mm; margin entire. Labellum slightly thickened, white, entire, narrow elliptic, obtuse, 2 x 1 mm when expanded; upper side with two calli bordering a central depression; base truncate; margin entire, winged and antrorse in basal and central part. Column white to greenish white, slender, curved inwards, 1,2 mm long; foot 0,5 mm long, with two minute calli; clinandrum winged, entire. Anther apical; pollinia 2, oblique, reni- to lentiform, sculpture psilate to punctate. Stigma ventral. Ovary 1 mm long, glabrous. Capsule 3-4 mm long, glabrous, ribbed. – Fl.: III-VI, Fr.: III-VII.

Distribution: Endemic in East Cuba: Ho, SC (Sierra del Cristal: headwaters of the Río Lebisa). Epiphytic; prefers shady and humid places in montane rainforests, mesophyllous evergreen rainforests and charrascales from 300 to 900 m, exclusively in vegetation on soils derived from serpentine. Scattered.

Fig. 15: Pleurothallis gelida Lindl.

1 – Plant. 2 –  Flower. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Fig. 16: Pleurothallis gemina H. Stenzel

1 – Plant. 2 – Flower. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Pleurothallis ghiesbreghtiana A. Rich. & Galeotti in Ann. Sci. Nat., Bot., ser. 3, 3: 16. 1845. Holotype: “Mexique, Province d' Oaxaca”, 1842, Ghiesbreght ex herb. Richard (P No. 226376 [photo!], W ex herb. Reichenbach Orch. No. 53684 [fragment of holotype]!). – .

=Pleurothallis longissima Lindl., Folia Orchid. Pleurothallis: 31. 1859. Holotype: “Pleurothallis racemiflora Nob., Hort. Loddiges” [Jamaica, according to Loddiges], 1824, Loddiges (K-L!).

–“Pleurothallis racemiflora” sensu Adams (1972: 107), Luer (1975a: 204, 2000: 79), Ackerman (1995: 132), Gloudon & Tobisch (1995: 176), Nir (2000: 299), Pridgeon & Chase (2001: 250) (non Pleurothallis racemiflora (Sw.) Lindl., non “Pleurothallis racemiflora Lindl. ex Lodd.” nom. inval.).

Herbs, caespitose and erect, 10-25 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls erect, 4-10 cm long, 2-articulated, completely or partially covered by three scarious sheaths; annulus present. Leaves fleshy, narrow elliptic to narrow oblong, obtuse to rounded, minutely tridentate, 6-12 x 1,5-3 cm, shiny green, slightly concave on [page 43↓]the upper side, convex on the lower side; base short attenuate; margin entire. Inflorescence a terminal raceme, erect, solitary, multi-flowered, subtended at the base by a conduplicate and acute sheath of 1-1,5 cm in length; peduncle erect, 1-5 cm long, with two bracts; axis erect, 4-11 cm long. Pedicels 5 mm long, free; bract membranous, tubular, oblique, acute, 3-4 mm long. Flowers resupinate, anthesis subsimultaneous. Sepals slightly thickened, yellowish, convex; margin entire; dorsal sepal barely basally connate with the lateral ones, narrow ovate, acute, 3-veined, 6-6,3 x 3-3,2 mm; the lateral ones connate to 1 mm below the tip, synsepal broadly elliptic to obovate, acute, bifid, carinate with minute warts on the keels, 6-veined, 6-6,3 x 3,5 mm. Petals membranous, yellowish, narrow ovate, acute, 3-veined, 5 x 2 mm; margin entire to slightly erose. Labellum thickened in the central portion, whitish, panduriform, trilobate, obtuse or retuse, 4 x 2 mm when expanded, midlobe suborbicular, the lateral ones broad, antrorse; upper side with two small calli in the middle; base truncate; margin crenulate to sinuate. Column whitish, slightly curved inwards, 3 mm long; foot 0,7 mm long; clinandrum winged with a denticulate margin. Anther apical; pollinia 2, obtusely triangular, sculpture punctate-octomeriaeform (s. Stenzel 2000). Stigma ventral. Ovary 2,5-3 mm long, glabrous, surcate. Capsule 7-8 mm long, ribbed. – Fl.: III-VIII, Fr.: III-X.

Distribution:Central America and Venezuela (Luer 2000), Antilles. Present in West Cuba: PR (Pan de Guajaibón). Epiphytic, lithophytic or pseudoterrestric in the litter layer; prefers shady to open places in dwarf forms of the montane rainforests from 600 to 700 m, in vegetation on limestone. Known only from one locality.

Fig. 17: Pleurothallis ghiesbreghtiana A. Rich. & Galeotti.

1 – Plant. 2 – Leaf, cross section. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Fig. 18: Pleurothallis grisebachiana Cogn.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis grisebachiana Cogn. in Urban, Symb. Antill. 6: 409. 1909. Lectotype (designated here): “prope villam Monte Verde dictam, Cuba Orientali, Jan.-Jul. 1859”, [San André, according to Cogniaux (1909)], Wright 1503 p.p. ex herb. Grisebach (GOET!). – .

=Pleurothallis blepharoglossa Luer in Lindleyana 14: 111. 1999. Holotype: “Cuba, [page 44↓]Holguín: Moa, Camino a La Melba, Arroyo Las Comadres”, 350 m, 29-XI-1997, Luer & al. 18654 (HAJB!; isotype MO [n.v.]).

–“Pleurothallis grobyi” sensu Lindley (1858: 326, 1860: 219), Nir (2000: 289) et auct. fl. cub. (non Pleurothallis grobyi Batem. ex. Lindl.).

Herbs, caespitose, 0,9-2 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, erect, 1,5-2 mm long, basally 3-articulated, entirely covered by three tubular sheaths; annulus present. Leaves slightly thickened, (narrow) spathulate, obtuse, minutely tridentate, 0,5-1,8 x 0,2-0,4 cm, green, glabrous; base narrow attenuate; margin entire or slightly erose in the upper part. Inflorescence a terminal raceme, ascending, solitary, 2-5(-10) flowers, subtended at the base by an ovate sheath of 0,5 mm in length; peduncle 0,5-1,5 cm long, with a bract; axis 0,5-3,5 cm long. Pedicels 1,2-2,2 mm long, fused to 0,5 mm with the axis; bract membranous, triangular, conduplicate, 0,8-1,1 mm long. Flowers resupinate, anthesis successive. Sepals membranous to slightly thickened along the nerves, yellow (sometimes with a tint of red), carinate; margin slightly papillose in the upper part; dorsal sepal free, narrow ovate, acute, 3-veined, 3,5-4,7 x 1,8-2,1 mm; the lateral ones connate to the tip, the base forming a mentum with the ovary, synsepal (narrow) ovate, bifid, 4-veined, 4-5,1 x 2,7-3 mm. Petals membranous, yellowish, narrow rhombic to spathulate, acute, 1-veined, 2-2,6 x 0,6-0,8 mm; margin serrulate or slightly crenulate. Labellum membranous, partially thickened, yellow with stripes of red, simple, narrow oblong, obtuse, 3-3,2 x 1 mm when expanded; upper side with two (rarely three) lengthwise red calli, bordering a central depression; base short clawed; margin ciliate, antrorse below the middle, papillose and revolute in the upper part. Column whitish, slender, carinate, 2,3 mm long; foot 1,4-1,6 mm long, with a elongated cavity and two orbicular calli; clinandrum winged, dentate at the tip; foot reddish. Anther apical; pollinia 2, spathulate, sculpture variably psilate or granulate. Stigma ventral. Ovary 0,9 mm long, glabrous. Capsule 3-4 mm long, glabrous, ribbed. – Fl.: II-VII, Fr.: II-VIII.

Distribution: Endemic in Central Cuba: Ci (Sierra de Escambray: lomas al sur of the Pico San Juan), SS; East Cuba: Ho, Gr (Guisa: Victorino; Río Jao), SC, Gu. Epiphytic or lithophytic; prefers shady and humid conditions in vegetation of the mogotes, gallery forests, montane rainforests, mesophyllous evergreen rainforests and secondary forests (cupeyales) from 300 to 800 m; indifferent to the type of the soil, on limestone as in vegetation on serpentine. Scattered.
Dod (1984: 107) includes “Pleurothallis grobyi” in a key of the species of Pleurothallis from Hispaniola, however, the description of the petals with an entire margin, does not correspond to the caracteristics of Pleurothallis grisebachiana. There are collection insertion IJ and NY which are anntoated as Pleurothallis grisebachiana, which in all cases show plants of Pleurothallis curtisii D.D.Dod.

Variability: Regarding coloration and size theis species is highly variable which prompted Luer to publish Pleurothallis blepharoglossa Luer as distinct taxon.

Pleurothallis helenae Fawc. & Rendle in J. Bot. 47: 4. 1909. ≡Specklinia helenae (Fawc. & Rendle) Pridgeon & M. W. Chase in Lindleyana 16: 258. 2001. Holotype: [uned. drawing] “Pleurothallis Helenae” [drawing by H. A. Wood, folios labelled “Botanical drawings by Miss Ward [sic!]”] (IJ!). Epitype (designated here): “Jamaica: Mt. Moses”, 1050 msm, Syme, J.P. [Jamaican Plants] 2279 (BM [ex herb. Morris] No. 82290!; isoepitype: NY No. 59937). – Fig. 19.

Herbs, caespitose, 0,7-1,6 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, 0,4-0,7 mm long, basally 2-articulated, entirely covered by two scarious, tubulosas sheaths; annulus present. Leaves slightly thickened, (narrow) spathulate, acute to obtuse, tridentate, 0,6-1,6 x 0,2-0,4 cm, green, glabrous; base narrow attenuate; margin entire. Inflorescence a terminal raceme, ascending, solitary, 2-6 flowers, subtended at the base by an ovate sheath of 0,4 mm in length; peduncle glabrous, filiforme, 1-1,8 cm long, with one bract; axis glabrous, slender, 0,5-1,7 cm long. Pedicels up to 4 mm long, free; bract membranous, triangular, conduplicate, reddish, 0,5-[page 45↓]0,8 mm long. Flowers resupinate. Sepals membranous, white and reddish, free, narrow ovate, slightly caudate, carinate; margin minutely papillose in the upper part; dorsal sepal 3-veined, 3-3,1 x 1 mm; the lateral ones slightly falcate, 2-veined, 3-3,1 x 1 mm. Petals membranous, hyaline, narrow ovate, acuminate, 1-veined, 2,5 x 1,1 mm; margin profoundly serrate to lacerate. Labellum membranous, partially thickened, white, oblong, trilobate, obtuse, short apiculate, 1,8-1,9 x 1,1-1,2 mm when expanded, midlobe thickened, broadly ovate with a circular disc, the lateral ones membranous, antrorse, serrate in the distal part; upper side with two central and short calli bordering a cavity; base truncate; margin minutely papillose in the upper part. Column whitish, curved inwards, 1,6 mm long; foot 0,4 mm long, with an elongated cavity; clinandrum slightly winged, denticulate. Anther apical; pollinia 2, amorphous, sculpture indistinct. Stigma ventral. Ovary 0,9 mm long, glabrous. Capsule 5-6 mm long, minutely papillose, ribbed. – Fl.: I-XII, Fr.: I-XII.

Distribution: Greater Antilles (except Puerto Rico). Present in East Cuba: Ho (Sierra del Cristal: cumbre), Gr (Victorino: Loma El Gigante), SC (Sierra Cobre: Loma del Gato; Gran Piedra). Epiphytic or lithophytic on twigs or rocks in mosses and lichens; prefers humid and partially open places like foggy mountain crests in elfin forests from 1000 to 1300 m, in vegetation on soils derived from serpentine or on volcanic rock. Rare.

Reproduction biology: The flowers set fruit without anthesis which suggests cleistogamy. This is indicated by the amorphous pollinia too.

Fig. 19: Pleurothallis helenae Fawc. & Rendle

1 – Plant. 2 – Flower. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Fig. 20: Pleurothallis llamachoi Luer

1+2 – Plant. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Pleurothallis llamachoi Luer in Lindleyana 13: 146. 1998. Holotype: “Cuba: Holguín, Mayarí, Sierra de Nipe, epiphytic in moist forest behind cabins of Agricultural Station”, 650 m, 25-XI-1997, Luer & al. 18631 (HAJB!; isotypes: MO [n.v.], UPRRP [n.v.]). – .

Herbs, caespitose, 1-2 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, 2-2,4 mm long, basally 2-articulated, entirely covered by two scarious sheaths; annulus present. Leaves slightly thickened, narrow elliptic to oblanceolate, acute and short apiculate, 0,8-1,7 x 0,2-0,25 cm, green, glabrous; base [page 46↓]narrow attenuate; margin denticulate beyond the middle. Inflorescence a terminal raceme, pendent or repent on or in the substrate, solitary, few-flowered, subtended at the base by an ovate sheath of 0,6 mm in length; peduncle glabrous, hair-like, 0,6-2 cm long, with a bract; axis glabrous, filiforme, 0,4-1,5 cm long. Pedicels 1,2-2,4 mm long, free or basally fused with the axis; bract membranous, triangular, conduplicate, reddish, 0,5-0,8 mm long. Flowers resupinate, anthesis successive. Sepals membranous and slightly thickened along the nerves, yellowish or whitish with purple stripes, lanceolate, carinate; margin entire; dorsal sepal free, apically attenuate to slightly caudate, 3-veined, 5-5,1 x 1,2-1,3 mm; the lateral ones connate almost to the middle, the base forming a mentum with the ovary, acute, 2-veined, 5-5,1 x 1,4 mm. Petals membranous, hyaline with purple nerves, oblique-spathulate, acute, 1-veined, 2,3-2,5 x 1,1-1,2 mm; margin profoundly serrate to lacerate in the upper part. Labellum slightly thickened, purple, narrow ovate, acute to subobtuse, 3,8-3,9 x 2-2,1 mm when expanded; upper side with two denticulate calli close to the margin and with purple stripes from the central portion to the marginal teeth; base truncate; margin serrate to fimbriate. Column light reddish, slender, curved inwards, 2,1 mm long; foot 0,6 mm long, with an elongated cavity; clinandrum winged and profoundly denticulate. Anther apical; pollinia 2, claviform, sculpture psilate. Stigma ventral. Ovary 0,7 mm long, glabrous. Capsule 3-4 mm long, glabrous, ribbed. – Fl.: III-VI, Fr.: III-VII.

Distribution: Endemic in East Cuba: Ho, Gu (Yateras: Pico Galán; Sierra Imías: Alto la Yamagua). Epiphytic; prefers humid and shady places in montane rainforests, gallery forests and charrascales from 400 to 900 m, restricted to the vegetation on serpentine rock. Rare.

Pleurothallis longilabris Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 328. 1858. Lectotype (designated here): “Cuba Orientali, 1856-7” [blue label], [Monte Verde, according to Wright in Lindley (1858)], Wright 651 p.p. (K-L!; isolectotypes?: AMES No. 72372!, G!, G ex herb. Barbey-Boissier!, GOET!, NY No. 59923!). – Fig. 21.

Herbs, caespitose, 1-2 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, 1,5-2 mm long, basally 4-articulated, entirely covered by 4 scarious, conduplicate, acute sheaths; annulus present. Leaves slightly thickened, narrow elliptic to oblanceolate, acute and short apiculate, 0,8-1,8 x 0,2-0,4 cm, green, glabrous; base narrow attenuate; margin denticulate. Inflorescence a terminal raceme, ascending to pendent, solitary, few-flowered, subtended at the base by an ovate sheath of 0,8 mm in length; peduncle glabrous, filiforme, 1-1,5 cm long, with a bract; axis glabrous, flexuosus, filiforme, 1-2,5 cm long. Pedicels 3-4,5 mm long, fused to 0,8 mm with the axis; bract membranous, triangular, conduplicate, 0,9-1,2 mm long. Flowers resupinate, anthesis successive. Sepals membranous and slightly thickened along the nerves, hyaline, purple or with purple stripes, the upper part yellow, narrow ovate, acute, carinate; margin entire; dorsal sepal free, 3-veined, 4,8-5 x 1,7-1,8 mm; the lateral ones basally connate by 1,5-2 mm, forming a mentum with the tip of the ovary, slightly falcate, 2-veined, 4,8-5 x 1,5-1,6 mm. Petals membranous, hyaline, linear, acute, 1-veined, 2,9-3 x 0,9-1,1 mm; margin denticulate to lacerate. Labellum membranous, whitish, purple dark and yellow, trilobate, emarginate, 4,4-4,6 x 2-2,1 mm when expanded, midlobe thickened, the lateral ones obtuse-triangular, antrorse, profoundly serrate in the distal portión; upper side with a longitudinal callus, apically covered with papillae and dentiform calli; base truncate; margin serrate in the middle, apically denticulate. Column whitish, slender, curved inwards, 2,2 mm long; foot 0,6 mm long; clinandrum winged, margin denticulate. Anther apical; pollinia 2, elongated, claviform, sculpture psilate. Stigma ventral. Ovary 0,9 mm long, glabrous, red. Capsule 3-4 mm long, glabrous, ribbed. – Fl.: III-VI, Fr.: III-VII.

Distribution: Endemic in East Cuba: SC (Sierra del Cristal: headwaters of Río Lebisa), Gu (Sierra Imías: Alto la Yamagua). Epiphytic; prefers humid and shady places in mesophyllous evergreen rainforests and montane rainforests from 500 to 600 m, restricted to the vegetation on serpentine rock. Rare.
The collection Picarda (IJ) [without flowers] from Haití has the habitus of P. longilabris. [page 47↓]However, this morphology is not exclusively confined to the latter but occurs in closely related taxa too (e.g. Pleurothallis aristata). It is little probable that a presumed Cuban endemic, that is very rare and restricted in Eat Cuba itself, may occur on the neighbouring island. Dod (1984: 104) too expresses his doubts towards the occurence of Pleurothallis longilabris on Hispaniola.

Fig. 21: Pleurothallis longilabris Lindl.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 22: Pleurothallis mucronata Lindl. ex. Cogn.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis mucronata Lindl. ex Cogn. in Urban, Symb. Antill. 6: 424. 1909. Lectotype (designated here): “Cuba”, Wright 1504 ex herb. Cogniaux (BR No. 843494!). – .

Herbs, caespitose, 0,5-1 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, densely aggregated, 0,8-1 mm long, basally 3-articulated, entirely covered by three membranous tubular and acute sheaths; annulus present. Leaves slightly thickened, elliptic to suborbicular, obtuse, short apiculate, 3-7(-9) x 3-3,5 mm, yellowish green and glabrous on the upper side, green and glabrous on the lower side; base short attenuate; margin minutely denticulate. Inflorescence a terminal raceme, ± straight, solitary, few-flowered; axis glabrous, filiforme, red, 1-5 cm long, subtended at the base by an ovate sheath of 0,7 mm in length; peduncle, 0,6-3 cm long, with various bracts; axis 0,4-2 cm long. Pedicels 2,5-4 mm long, fused to 0,9 mm with the axis; bract membranous, narrow triangular, conduplicate, 1-1,3 mm long. Flowers resupinate, anthesis successive. Sepals membranous, yellowish or whitish, often with a tint of red or reddish striped, carinate; margin entire; dorsal sepal connate basally with the lateral ones, narrow ovate, acuminate, 3-veined, 4-4,7 x 1,9-2 mm; the lateral ones connate basally and adnate up to the middle, the base forming a mentum with the ovary, lanceolate, short caudate, 2-veined, 4-4,6 x 1,1-1,2 mm. Petals membranous, yellowish and reddish, oblong to oblanceolate, acute, 1-veined, 2,5-2,6 x 1 mm; margin denticulate or crenulate above the middle. Labellum membranous and slightly thickened, yellowish and red, oblong, trilobate, subacute to obtuse, 2,5 x 1,6-1,7 mm when expanded, midlobe broadly oblong, slightly thickened, papillose, the lateral ones dentiform, antrorse; upper side with two papillose calli in the middle; base truncate; margin papillose. Column whitish, slender, 1,6-1,8 mm long; foot 0,5 mm long, with an elongated cavity; clinandrum winged and dentate in the tip, purple. Anther apical; pollinia 2, obtusely triangular, [page 48↓]sculpture psilate. Stigma ventral. Ovary 0,6 mm long, glabrous, red. Capsule 2-3,5 mm long, glabrous, ribbed. – Fl.: III-VI, Fr.: III-VII.

Distribution: Endemic in East Cuba: Ho, SC (Sierra del Cristal: headwaters of Río Lebisa), Gu (Sierra Imías: Alto la Yamagua). Epiphytic; prefers humid and shady to partially open conditions, usually along rivulets in gallery forests or rarely in montane rainforests from 500 to 800 m, restricted to the vegetation on serpentine rock. Scattered.

Pleurothallis murex Rchb. f. in Flora 48: 276. 1865. Holotype: “Cuba, 1860-1864”, Wright 3348 (K!; isotypes?: AMES No. 72375 [photo!], BM No. 82331!, BR No. 843498!, G ex herb. Barbey-Boissier!, G ex herb. de Candolle!, GOET!, HAC ex herb. Sauvalle No. 3175!, W ex herb. Reichenbach Orch. No 54724! [fragment of lectotype?]). – Fig. 23.

–“Pleurothallis trigonifolia et tuberculata” according to Lindley (1860: 219) (nomina nuda).

Herbs, subcaespitose, 1,5-3 cm high (excluding the inflorescence). Rhizomevery short, separating the ramicauls by < 1 mm. Ramicauls elongated, ascending to pendent, 1-2,2 cm long, basally 1-articulated, covered below the middle by 1-2 scarious sheath; without an annulus. Leaves thickened, triangular in transverse section, broadly ovate to suborbicular, rounded to obtuse, short apiculate, 0,5-0,8 x 0,4-0,6 cm, green and verrucate on the upper side, green and rough on the lower side; base obtuse to rounded; margin irregularily denticulate to profoundly crenulate with crenae up to 1 mm long (in sicco). Inflorescence a terminal raceme, pendent or ascending, 1-5 per stem, few-flowered, subtended at the base by a conduplicate, carinate and crenate sheath of up to 2 mm in length; peduncle glabrous, 0,7-1,5 cm long, with two or three bracts; axis glabrous, slightly flexuosus, 0,3-1,5 cm long. Pedicels 1-1,5 mm long, fused below the middle with the axis; bract membranous, infundibuliform, up to 1 mm long. Flowers resupinate, anthesis successive. Sepals membranous and slightly papillose along the nerves, yellowish and basally with a tint of red, carinate; margin somewhat papillose; dorsal sepal basally connate with the lateral ones, narrow obovate, acute, 1-veined, 2,7 x 1 mm; the lateral ones connate to 4/5, synsepal broadly ovate, rounded, bilobeds, 4-veined, 2,5 x 2 mm. Petals membranous, hyaline, spathulate, apiculate, 1-veined, 1,1 x 0,6 mm; margin serrate in the upper part. Labellum membranous, yellowish, spathulate, trilobate, obtuse to rounded, 2 x 1,2 mm when expanded, midlobe oblong-orbicular, the lateral ones rhombic, antrorse, crenulate; upper side with two central and two basal callis; base truncate; margin papillose in the upper part. Column whitish, claviforme, 1,5 mm long; foot 0,4 mm long; clinandrum distinctly winged and apically serrate. Anther apical; pollinia 2, suborbicular, sculpture vermiculate-granulate. Stigma ventral. Ovary 0,5 mm long, papillose. – Fl.: XI, Fr.: XI-XII.

Distribution: Endemic in Central Cuba: SS (Yaguajay: Loma la Canoa); East Cuba: Gu (Sierra of the Frijol: Laga of the Galano). Epiphytic; prefers semi open places in vegetation of the mogotes or charrascales in 200 and 1000 m, in vegetation on soils derived from limestone or serpentine rock. Rare. Apart from the type collection only twice recollected.
Dod (1984: 107) and Nir (2000: 295) include Pleurothallis murex in the flora of Hispaniola, based on Dod 142. However, the fimbriate petals and lip do not coincide with the Cuban plants.

Pleurothallis nummularia Rchb. f. in Flora 48: 276. 1865. ≡Phloeophila nummularia (Rchb. f.) Garay in Orquideologia 9: 118. 1974. Lectotype (designated here): “Cuba: Monte Verde, Jan.-Jul. 1859, Wright 1513” [handwritten label], Wright 1513 (W ex herb. Reichenbach Orch. No. 42681!; isolectotypes?: GOET!, K!, K-L!). – Fig. 24.

Herbs, repent, prostrate. Bracts, sheaths, ovary and capsule generally purplish hirsute. Rhizome elongated, separating the ramicauls by 2‑4 mm long and covered by three tubular, scarious sheaths. Ramicauls very short, 0,2‑0,5 mm long, 2-articulated, entirely covered by two scarious sheaths; without an annulus. Leaves coriaceous, suborbicular, [page 49↓]rounded to obtuse-retuse, tridentate, 3-4,5 x 2-3 mm, dark green to purple, verrucate; base obtuse to short attenuate; margin slightly crenulate. Inflorescence terminal, erect, solitary, single-flowered; peduncle purple, without bracts, 0,8-1,4 cm long, basally subtended by a oblique, conduplicate sheath of 0,8 mm in length. Pedicels 2 mm long; bract membranous, infundibuliform, 2 mm long. Flowers resupinate. Sepals membranous, brownish purple, carinate; margin entire; dorsal sepal free, (narrow) ovate, acute, 3-veined, 5,5-6,0 x 3,5 mm; the lateral ones entirely connate, synsepal ovate, acute to obtuse, 6-veined, 5,5-6,0 x 3,5? mm. Petals membranous, yellowish green [Wright in herb.], narrow oblong, acute, 3-veined, 3 x 0,7 mm; margin denticulate and ciliate in the upper part. Labellum slightly thickened, yellowish green and basally, mottled with purple [Wright in herb.], linguiform to pandurate, slightly trilobate, acute to obtuse, 2,5 x 0,8 mm when expanded; base truncate; margin antrorse below the middle, serrate in the upper part. Column yellowish green [Wright in herb.], slender, curved inwards, 2,5 mm long; foot 1 mm long; clinandrum winged. Anther apical; pollinia 2. Stigma ventral. Ovary 0,5 mm long. Capsule 1 cm long. – Fl.: III-VI, Fr.: III-VII.

Distribution: Cuba and Jamaica. Present in East Cuba: Ho (Sierra Nipe: Pinares Mayarí, La Caridad), SC (Sierra del Cristal: headwaters of the Río Lebisa), Gu (Sierra Imías: Alto la Yamagua). Epiphytic, on trunks; prefers humid conditions in gallery forests and montane rainforests from 500 to 700 m, in Cuba restricted to the vegetation on serpentine rock. Very rare. There is one collection from Jamaica (Hespenheide!: Cockpit Country, on limestone).

Fig. 23: Pleurothallis murex Rchb. f.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 24: Pleurothallis nummularia Rchb. f.

1 – Plant. 2 – Flower. 3 – Petal. 3 – Lip.
5 – Hair.

Pleurothallis obliquipetala Acuña & C. Schweinf. in Bot. Mus. Leafl. 6(1): 3. 1938. ≡Trichosalpinx acunae Luer in Phytologia 54: 394. 1983. Holotype: “Cuba, Oriente, Estribo del Este, Pico Turquino”, 1650 msm, 01-VIII-1935, Acuña 9540 (HAC!; isotypes: AMES No. 46830!, HAC ex herb Roig. No. 6644!, NY No. 59686 ex herb Roig. No. 6644!). – .

Herbs, caespitose, 0,8-1,7 cm high. Rhizome reduced. Ramicauls very short, 1-1,5 mm long, basally 3-articulated, entirely covered by three membranous sheaths; annulus [page 50↓]present. Leaves thickened, narrow elliptic to oblanceolate, acute to subobtuse, short apiculate, 0,7-1,4(-1,6) x 0,2-0,3 cm, green on the upper side, green-purple on the lower side, glabrous; base narrow attenuate; margin minutely denticulate. Inflorescence a terminal, solitary raceme, erect, 2(-3) flowers, subtended at the base by an ovate sheath of 0,8 mm in length; peduncle glabrous, 1,5-2,5 mm long, with a bract; axis glabrous, 1-2 mm long. Pedicels 1-1,6 mm long, barely basally fused with the axis; bract membranous, tubular to infundibuliform, 0,9-1,1 mm long. Flowers resupinate, anthesis successive. Sepals membranous and slightly thickened along the nerves, whitish with purple stripes and yellow tips, carinate; dorsal sepal connate basally with the lateral ones, lanceolate, apically attenuate to slightly caudate, 3-veined, 3,9-4,1 x 1,1 mm; margin entire; the lateral ones connate up to the middle, ovate, falcate, caudate, 2-veined, 4,2-4,3 x 1,6 mm; margin minutely denticulate in the middle. Petals membranous, hyaline and purple, oblique rhombic, acute, 1-veined, 2 x 1 mm; margin denticulate in the upper part. Labellum slightly thickened, purple, oblong, trilobate, obtuse, 3-3,1 x 1,3 mm when expanded, midlobe oblong, carinate and papillose, the lateral ones ± straight, papillose, antrorse; upper side with two elongated verrucate calli; base truncate; margin papillose or crenulate. Column whitish and purple, slender, curved inwards, 1,8-1,9 mm long; foot 0,7 mm long, with an elongated cavity; clinandrum distinctly winged and apically denticulate. Anther apical; pollinia 2, elongated, claviform, sculpture psilate. Stigma ventral. Ovary 0,6 mm long, glabrous, red. Capsule 3-3,5 mm long, glabrous, ribbed. – Fl.: VIII-I, Fr.: VIII-II.

Distribution: Endemic in East Cuba: Gr (Sierra Maestra: falda norte of the Pico Turquino), SC (Sierra Maestra: Pico Turquino; Sierra del Cobre: Loma del Gato; Gran Piedra). Epiphytic or lithophytic on base of trunks or on rocks; prefers shady and humid places in montane rainforests and cloud forests from 1100 to 1700 m, in vegetation on soils derived from volcanic rock. Rare.

Fig. 25: Pleurothallis obliquipetala Acuña & C. Schweinf.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 26: Pleurothallis obovata (Lindl.) Lindl.

1 – Plant. 2 – Flower. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Pleurothallis obovata (Lindl.) Lindl. in Bot. Reg. 28: misc. 75, no. 51. 1842. ≡Specklinia obovata Lindl. in Bot. Reg. 25: misc. 86, no. 137. 1839. ≡Anathallis obovata (Lindl.) Pridgeon & M. W. Chase in Lindleyana 16: 250. 2001. Lectotype (Luer 1999: 115): [page 51↓]“Specklinia obovata” [Brasil], anón. (K-L!). – .

=Pleurothallis albida Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 327. 1858. Holotype: “in Cuba Orientali, 1856-7” [blue label], Wright 655 (K-L!; isotypes?: G ex herb. Barbey-Boissier!, K!).

Herbs, repent, 7-20 cm high. Rhizome elongated, separating the ramicauls by 4-15 mm, covered by three membranous sheaths of light brown. Ramicauls erect or ascending, lengthwise surcate (in sicco), 2,5-12 cm long, 4-5-articulated, partially covered by 4-5 sheaths; annulus present. Leaves coriaceous, narrow obovate, oblanceolate or subspathulate (rarely narrow elliptic), obtuse to rounded, rarely subacute, minutely tridentate, 4,5-9 x 1,7-2,8 cm, green, glabrous; base narrow attenuate; margin entire, slightly revolute. Inflorescence a terminal few-flowered raceme, 2-8 per stem, subtended at the base by an ovate and laterally compressed sheath of 0,5 cm in length; peduncle filiforme, 2 mm long, with a bract; axis fine, flexuosus, 3-13(-18) mm long. Pedicels up to 4 mm long, fused below the middle with the axis; bract membranous, infundibuliform or triangular, up to 3 mm long. Flowers resupinate, anthesis successive or simultaneous. Segments membranous, whitish to yellowish, acute; margin entire. Sepals 3-veined; dorsal sepal connate barely basally connate with the lateral ones, narrow ovate, 4,8-5,4 x 1,7-1,8 mm; the lateral ones connate basally by 1 mm, lanceolate to triangular, slightly falcate, 4,7-5,2 x 1,2-1,3 mm. Petals subulate, 1-veined, 4-4,2 x 1 mm. Labellum slightly thickened, yellowish, simple, narrow obovate to oblong, acute, 2,2-2,4 x 0,9 mm when expanded; base slightly papillose, truncate with two small lateral lobes; margin entire, apically revolute. Column whitish, 2 mm long; foot 0,7 mm long, with a cavity elongated; clinandrum distinctly winged and serrate. Anther apical; pollinia 2, pyriform, sculpture gemmate. Stigma ventral. Ovary 0,5-1 mm long, glabrous. Capsule 0,5 cm long, globose, glabrous, ribbed. – Fl.: VI-XII, Fr.: VI-I.

Distribution: Central America, Venezuela, Colombia (Luer 1999), Brasil, Greater Antilles (except Jamaica). Present in East Cuba: Gr, Ho, SC, Gu. Epiphytic or lithophytic; prefers open or shady places like rocks or the canopies of the trees in vegetation of the mogotes, mesophyllous evergreen rainforests, gallery forests and secondary forests (cupeyales) from 500 to 900 m, indifferente to the type ot the soil. Scattered.

Pleurothallis odontotepala Rchb. f. in Flora 48: 275. 1865. Holotype: “Cuba, 1860-1864”, Wright 3349 (K!; isotypes?: AMES No. 72381 [photo!], K ex herb. Prior!). – Fig. 27.

=Pleurothallis brachypetala Griseb., Cat. Pl. Cub.: 257. 1866. Holotype: “721, Cuba occ. Wr. 3349b, 1863” [handwritten label], Wright “3349b” (GOET!).

Herbs, subcaespitose, 3-7(-9) cm high. Rhizome reduced. Ramicauls erect or ascending, laterally compressed, lengthwise surcate, carinate, 1-4 cm long, basally 3-articulated, covered by three tubular, conduplicate sheath to beyond the middle; without an annulus. Leaves coriaceous, narrow ovate to elliptic, acute, tridentate, 2-5 x 0,8-1,8 cm, green, glabrous, carinate; base short attenuate to obtuse; margin entire, slightly revolute. Inflorescence a terminal raceme, ascending or prostradas on the foliar limb, 1-4(-7) per stem, 2-7 flowers, glabrous, subtended at the base by a conduplicate and acute sheath of 0,3-0,5 cm in length; peduncle rigid, 0,3-0,8 cm long, with a bract; axis rigid, 0,5-1 cm long. Pedicels 1,6-1,8 mm long, fused by 4/5 su longitud with the axis; bract slightly thickened, tubular, acute, carinate, 1,8-2 mm long. Flowers thickened, resupinate, anthesis successive or subsimultaneous . Sepals green with purple stripes, 3-veined, carinate, connate basally; margin papillose in the upper part; dorsal sepalpandurate, apically papillose on the inner side, obtuse or acute, 5,2-5,3 x 1,7-1,8 mm; the lateral ones free but adnate to 3 mm, ovate, falcate, acute, 4,9-5,1 x 2,1-2,5 mm. Petals light reddish, oblanceolate to spathulate, acute to short acuminate, 1-veined, 2-2,1 x 0,7-1 mm; margin minutely serrate in the upper part. Labellum purple, oblong to narrow obovate, trilobate, obtuse or acute, 2,9-3,1 x 1,8-1,9 mm when expanded, midlobe broadly ovate, papillose, the lateral ones rounded, antrorse; upper side lengthwise with two crenulate papillose calli, bordering a central verrucate disc; base cordate and short clawed; margin [page 52↓]crenulate or papillose beyond the middle. Column light reddish to purple, curved inwards, 1,9-2 mm long; foot 0,9-1 mm long, with an elongated depression; clinandrum winged. Anther apical; pollinia 2, obtusely triangular to suborbicular, sculpture granulate. Stigma ventral. Ovary 1-1,2 mm long, glabrous, surcate. Capsule 10-12 mm long, glabrous, ribbed. – Fl.: II-X, Fr.: II-XI.

Distribution: Greater Antilles (Jamaica and Cuba; Hispaniola fide Dod 1984: 105). Present in East Cuba: Gr (Sierra Maestra, Turquino, Buey Arriba, Pico Verde), SC (Gran Piedra). Epiphytic; prefers shady and humid places in montane rainforests from 600 to 1300 m, in vegetation on soils derived from volcanic rock. Locally common.

Fig. 27: Pleurothallis odontotepala Rchb. f.

1 – Plant. 2 – Leaf shape variant. 3 – Flower. 4+5 – Sepals. 6 – Petal. 7 – Lip. 8 – Lip, ovary and column in natural position.

Fig. 28: Pleurothallis oricola H.Stenzel

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis oricola H. Stenzel in Willdenowia 32(1): 101. 2002. Holotype: “Cuba: Pinar del Río, Peninsula de Corrientes, en el camino de María la Gorda a Cabo Corrientes, bosque siempreverde micrófilo sobre diente de perro, sobre Vitex guanahacabibensis Borhidi”, Urquiola & al. (HAJB!; isotype: B!, HPPR!). – .

Herbs, repent, 0,6-1,2 cm high. Rhizome short, separating the ramicauls by 1-2 mm long and covered by three scarious, somewhat conduplicate sheaths. Ramicaulsvery short, up to 0,5 mm long, 2-articulated, entirely covered by two scarious and hyaline sheaths; without an annulus. Leaves thickened, elliptic or slightly oblanceolate, prostrate, acute, short mucronate or apiculate, 0,5-0,8 x 0,2-0,4 cm, green to greyish green, verrucate on the upper side, glabrous on the lower side; base (short) attenuate; margin crenulate to erose. Inflorescence terminal, two per stem, single-flowered; peduncle 2 mm long, basally with an ovate bract 1 mm long. Pedicels and bract up to 1 mm long; bract membranous, oblique, slightly conduplicate. Flowers resupinate. Sepals membranous and slightly thickened along the nerves, greenish, mottled with purple, carinate; margin entire or papillose; dorsal sepal connate basally with the lateral ones, lanceolate, acute, 3-veined, 4-4,5 x 1 mm; the lateral ones connate basally but adnate almost up to the tip, the base forming a mentum with the ovary, synsepal ovate, bifid, 6-veined, 4-4,5 x 3 mm. Petals membranous, whitish, nerves and base purple, oblique oblanceolate, acute, 1-veined, 2,5 x 1 mm; margin dentate. Labellum thickened in the middle and membranous [page 53↓]in the marginal parts, yellowish, mottled with purple, ovate, trilobate, obtuse, 3,2 x 2,5 mm when expanded, midlobe oblong, densely covered by dentiform calli, the lateral ones antrorse; upper side with a cavity basal and two calli lengthwise verrucate in the middle; base clawed, biauriculate; margin crenulate to erose in central part, serrate to denticulate above. Column yellow, mottled with purple, slightly curved inwards, 2 mm long; foot 0,6 mm long, with two calli; clinandrum slightly winged, serrate or dentate in el margen. Anther apical; pollinia 2. Stigma ventral. Ovary 1 mm long, somewhat papillose or verrucate. Capsule up to 0,5 cm long, with ribs slightly verrucate. – Fl.: IV-V, Fr.: V.

Distribution: Endemic in West Cuba: PR (Guanahacabibes: between Cabo Corrientes and Maria La Gorda). Epiphytic; prefers open to shady places in mesophyllous evergreen rainforests in low elevations, exclusively in vegetation on limestone. Known from only one locality.

Fig. 29: Pleurothallis papulifolia Luer

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 30: Pleurothallis prostrata Lindl.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis papulifolia Luer in Lindleyana 14: 116. 1999. Holotype: “Cuba, Moa, entre Alto de la Calinga y el Toldo, suelo serpentina”, 21-IV-1985, Panfet & Silva (HAJB!). – .

Herbs, subcaespitose, 1,5-4 cm high (excluding the inflorescence). Rhizomevery short, separating the ramicauls by 0,5-1 mm and covered by two tubular sheath. Ramicauls erect or ascending, 0,5-2 cm long, 3-articulated, completely covered by three infundibuliform, conduplicate and acute sheaths; without an annulus. Leavesthickened, oblanceolate or obovate to spathulate, rounded to retuse, 1-3,2 x 0,4-0,7 cm, green, verrucate on the upper side, glabrous and carinate on the lower side; base attenuate; margin entire. Inflorescence a terminal raceme, ascending, 1-3 per stem, 2-6 flowers, subtended at the base by an ovate sheath of 1,8-2,2 mm in length; peduncle glabrous or with minute warts, 0,8-1,5(-2,5) cm long, with two bracts; axis slightly flexuosus, glabrous or with papillae, 0,7-2,0 cm long. Pedicels 1-1,3 mm long, fused below the middle with the axis; bract membranous, triangular, often minutely papillose, 1,6-1,8 mm long. Flowers resupinate or not, anthesis successive. Sepals slightly thickened, yellowish or greenish, the nerves red, 3-veined, acute, papillose-carinate; margin entire or minutely papillose; [page 54↓] dorsal sepal free, oblong-oblanceolate, 5-5,2 x 1,5-1,7 mm; the lateral ones adnate to ¾, lanceolate, 5,4-5,5 x 1,6-1,7 mm. Petals membranous, hyaline, light purple, oblong-spathulate, acute, 1-veined, 2,5-2,6 x 0,7-0,8 mm; margin minutely denticulate in the upper part. Labellum thickened, purple, oblong, slightly trilobate, obtuse, 3,1-3,2 x 1,4 mm when expanded, midlobe oblong, papillose to granulate, the lateral ones glabrous, antrorse; upper side lengthwise with two calli, granulate in the middle; base abruptly attenuate, minutely biauriculate; margin thickened, verrucate to crenulate in the central and apical porción. Column pale green, curved inwards, 1,9-2 mm long; foot 0,7-0,8 mm long; clinandrum winged and apically denticulate, purple. Anther apical; pollinia 2, obovate, sculpture punctate to fossulate. Stigma ventral. Ovary 0,8 mm long, papillose. Capsule 6-7 mm long, papillose-ribbed. – Fl.: II-V, Fr.: II-VI.

Distribution: Endemic in East Cuba: Ho, Gu. Lithophytic or epiphytic; prefers open and humid places like the banks of rivulets in gallery forests, charrascales and pine-forests from 100 to 700 m, restricted to the vegetation on serpentine rock. Rare.

Ecology: Plants growing on river banks stand temporal inundations during the rainy season.

Pleurothallis prostrata Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 327. 1858. Lectotype (Luer 2000: 47, specified here): “in Cuba Orientali, 1856-7” [blue label], [Monte Verde, according to Wright in Lindley (1858)], Wright 629 (K-L!; isolectotypes?: AMES No. 72383 [photo!], BR No. 843509!, G!, G ex herb. Barbey-Boissier!, G ex herb. de Candolle!, GOET!, K!, W ex herb. Reichenbach Orch. No. 42708!). – Fig. 30.

Herbs, caespitose, pendent, 2-5(-6) cm high (excluding the inflorescence). Rhizome reduced. Ramicauls elongated, straight, surcate and carinate, 0,4-1,4 cm long, 3-articulated, entirely covered by three conduplicate sheaths; without an annulus. Leavescoriaceous and rigid, (linear) elliptic, acute, tridentate, 1,6-4,5 x 0,4-0,8 cm, green, glabrous, carinate; base acute to cuneate; margin minutely serrate. Inflorescence a terminal raceme, pendent, 1-3 per stem, 1-5 flowers, subtended at the base by a conduplicate and acute sheath of 2-3 mm in length; peduncle rough, 1-2 cm long, with two bracts; axis rough, flexuosus, 1-5 cm long. Pedicels 0,5 mm long, fused with the axis; bract slightly rigid, falcate, conduplicate, papillose along the keel, 2,8-3,2 mm long. Flowers resupinate because of the pendent inflorescence, anthesis successive. Sepals thickened and rigid, greenish,, mottled with purple, papillose-carinate, acute, apically slightly recurved; margin entire or minutely papillose; dorsal sepal free, narrow elliptic, 3-veined, 9,8-10 x 2-2,2 mm; the lateral ones connate basally but adnate up to the tip, the base forming a mentum with the ovary, synsepal ovate, 6-veined, 8,7-9,2 x 4,5-5,0 mm. Petals membranous, hyaline, purple, elliptic, acute, 1-veined, 4,3-4,5 x 1,6 mm; margin apically serrate. Labellum thickened, whitish and purple, oblong, lengthwise plicate, slightly trilobate, obtuse to rounded, 3,2-3,3 x 2 mm when expanded, midlobe broad, verrucate, basally with two curled lobes, the lateral ones less distinct, obtuse, antrorse; upper side with two lengthwise granulate calli; base minutely auriculate; margin thickened, papillose to crenulate in el ¾ superior. Column greenish and purple, curved inwards, 2,5 mm long; foot 1,2 mm long, with a elongated, shallow cavity; clinandrum distinctly winged, apically denticulate. Anther apical; pollinia 2, obtusely triangular, sculpture punctate to granulate. Stigma ventral. Ovary 0,9-1,2 mm long, papillose. Capsule 6-7 mm long, verrucate, ribbed. – Fl.: II-V, Fr.: II-VI.

Distribution: Endemic in East Cuba: Ho (Sierra del Cristal; Río Cabonico; Sierra Moa), Gu (Yateras: Pico Galán). Epiphytic; prefers humid and shady places in gallery forests, montane rainforests, charrascales from 600 to 800 m, exclusively in the vegetation on serpentine rock. Very rare.

Ecology: Apparently restricted to an arborescent species of the genus Senecio as phorophyte (Wright in herb. and pers. observ. in the field).


[page 55↓]

Fig. 31: Pleurothallis pruinosa Lindl.

1 – Plant. 2 – Fruit with persistent flower.
3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, column and ovary in natural position.

Fig. 32: Pleurothallis racemiflora (Sw.) Lindl.

1+2 – Plant. 3 – Rhachis with fruit.
4+5 – Sepals. 6 – Petal. 7 – Lip. 8 – Lip, column and ovary in natural position.

Pleurothallis pruinosa Lindl. in Bot. Reg. 28: misc. 75, no. 55. 1842. Holotype: “Surinami, ad ramos Crescentiae, flores flavescentes”, I-1838, Splitgerber 527 (K-L!; isotype: W ex herb. Reichenbach Orch. No. 17554!). – .

=Pleurothallis brachyglottis Rchb. f. in Flora 48: 275, 1865. Holotype: “Cuba, 1860-1864”, [Monte Verde, 28-VIII, according to Wright in AMES], Wright 3344 (K!; isotypes?: AMES No. 72361 [photo!], GOET [n.v.]).

Herbs, subcaespitose to slightly repent, 4-9(-11) cm high (excluding the inflorescence). Rhizomevery short, separating the ramicauls by 0,5-1 mm, covered by two sheaths. Ramicauls slender, erect or ascending, with base decumbente, 1,5-5(-7) cm long, 3-articulated, partially covered by three carinate sheaths of light brown color; without? an annulus. Leaves fleshy, narrow oblong-ovate or elliptic, acute to obtuse, minutely tridentate, 2,7-4 x 0,4-0,7 cm, green, glabrous; base acute to obtuse; margin entire. Inflorescence a terminal raceme, ascending or prostrate on the foliar limb, 1-4 per stem, 2-10 flowers, subtended at the base by a lanceolate, conduplicate, acute sheath of 0,5-0,7 cm in length; peduncle capillary, ascending, 0,5-1,5 cm long, with a bract; axis capillary, slightly flexuosus, 0,3-3 cm long. Pedicels 1-2 mm long, fused below the middle with the axis; bract membranous, tubular, obtuse, 1-2,5 mm long. Flowers resupinate. Sepals slightly thickened, whitish to yellowish; margin entire; dorsal sepal free, narrow ovate, acute, 3-veined, 2,5-2,6 x 0,9-1 mm; the lateral ones connate to the tip, synsepal ovate, subobtuse, 2-veined, 2-2,1 x 1,2-1,7 mm. Petals membranous, whitish, subulate, slightly falcate, acute, 1-veined, 1,9-2 x 0,25-0,3 mm; margin glabrous. Labellum thickened, whitish, narrow elliptic, slightly trilobate, acute, 1,4 x 0,8 mm when expanded, midlobe ovate, the lateral ones ± rectangular; upper side with two calli in the middle, bordering a shallow, suborbicular cavity; base truncate; margin minutely crenulate, antrorse. Column whitish, straight, thick, 0,8 mm long; foot reduced; clinandrum reduced. Anther apical with a reduced cap; pollinia 2, obovate or amorphous, sculpture psilate to lepanthiform (s. [page 56↓]Stenzel 2000). Stigma ventral. Ovary 2,5-3 mm long, glabrous, surcate. Capsule 7-8 mm long, glabrous. – Fl.: III-VI, Fr.: III-VII.

Distribution: Central America (Luer 1999), North of South America to Peru and the Guyanas, Antilles. Present in Central Cuba: SS (Trinidad); East Cuba: Ho (Sierra del Cristal: Río Lebisa), SC (Sierra del Cristal: headwaters of the Río Lebisa; Sierra Maestra: Loma del Gato), Gu. Epiphytic or lithophytic; prefers humid and shady places in mesophyllous evergreen rainfores, gallery forests and vegetation of the mogotes from 200 to 600 m, on limestone. Rare.

Reproduction biology: Some characteristics, like the generally closed flowers (Wright in herb. and pers. observ.) and the amorphous pollinia with a reduced and fragile exinous layer, suggest autogamy and probably cleistogamy in most of the Greater Antillean plants.

Pleurothallis racemiflora (Sw.) Lindl. in Exot. Fl. 2: t. 123 [excl. fig. & descr.]. 1824. ≡Epidendrum racemiflorum Sw., Prodr.: 125. 1788. ≡Dendrobium racemiflorum (Sw.) Sw. in Nova Acta Regiae Soc. Sci. Upsal. 6: 83. 1799. Lectotype (Fawcett & Rendle 1910: 55, specified here): “Epidendrum racemiflorum Swartz”, Jamaica, Swartz (BM No. 82214!; isolectotypes?: B ex herb. Willdenow No. 16896, G [n.v.], M [n.v.], S [photo!], S ex herb. Alstroemer [photo!], S ex herb. Swartz [photo!], W ex herb. Reichenbach Orch. No. 26616!). – Fig. 32.

=Pleurothallis oblongifolia Lindl. in Comp. Bot. Mag. 2: 355. 1837. ≡Stelis oblongifolia (Lindl.) Pridgeon & M. W. Chase in Lindleyana 16: 265. 2001. Holotype: “Jamaica, Loddiges”, 12-XI-1836 [cultivated], Loddiges (K-L!).

=Pleurothallis multirostris Rchb. f. in Linnaea 41: 49. 1877. Holotype: “E Jamaica allata. H.K. 9/73” [collected 1871 at Thompson Gap, flowered in Kew 8-IX-1873 according to Reichenbach in W], 8-IX-1873, anon. (K!).

=Pleurothallis tricostata Cogn. in Urban, Symb. Antill. 7: 175. 1912. Lectotype (designated here): [unedited drawing] “H. v. Türckheim no. 3481” [drawing by Cogniaux based on the holotype] (BR No. 843536!). Epitype (designated here): “República Dominicana: Prov. Azua, Las Lagunas”, 750 msm, 12-VI-1926, Ekman 6343 (K!; isoepitype: S [n.v.]).

–“Pleurothallis racemiflora” sensu Luer (2000: 80) and Pridgeon & Chase (2001: 250,266) (non “Pleurothallis racemiflora Lindl. ex Lodd.”, nom. inval.).

Herbs, subcaespitose, 10-20 cm high (excluding the inflorescence). Rhizomevery short, separating the ramicauls by 1-2 mm, covered by two scarious sheaths. Ramicauls erect or ascending, 6-11 cm long, 2- articulated, partially covered by three scarious, conduplicate and carinate sheaths; annulus present. Leaves coriaceous, elliptic to obovate, obtuse to rounded-retuse, 4-9 x 1-2,5 cm, green, glabrous; base attenuate; margin entire. Inflorescence a terminal raceme, erect, solitary, multi-flowered, subtended at the base by a narrow oblong, falcate, laterally compressed sheath of 1-3,5 cm in length; peduncle straight, rigid, 3-10 cm long, with two bracts; axis 2-9 cm long, often flexuosus when fruit-bearing. Pedicels 4-5(-8) mm long, fused by 1-2 mm with the axis; bract membranous, infundibuliform, 2-4 mm long. Flowers resupinate, anthesis subsimultaneous. Sepals membranous and slightly thickened along the nerves, green-purple; margin involute, ciliate in the upper part; dorsal sepal free, lanceolate, acuminate, 3-veined, 8,5-9 x 2,3-2,6 mm; the lateral ones connate almost up to the tip, synsepal narrow ovate, acute, bifid, 6-veined, 8,5-9 x 4 mm. Petals slightly thickened, light reddish and purple, oblong, rounded to emarginate, 3-veined, internally along the nerves and in the upper part on the outside verrucate, 2,9-3,2 x 2-2,2 mm; margin papillose or erose. Labellum thickened and membranous, reddish, simple, oblong, acute, 3,7-3,9 x 1,8-2 mm when expanded; upper side in the middle with two less distinct calli and above the middle with two transverse calli; base abruptamente attenuate; margin entire and antrorse in the basal portion, apically crenulate, verrucate and revolute. Column light reddish, straight, [page 57↓]2,2 mm long; foot 0,8 mm long; clinandrum slightly winged. Anther apical; pollinia 2, obovate, sculpture octomeriaeform. Stigma ventral. Ovary 2-2,4 mm long, glabrous or verrucate, greenish purple. Capsule 1 cm long, ribbed. – Fl.: VI-X, Fr.: VI-XI.

Distribution: Greater Antilles. Present in West Cuba: PR (La Palma: Río San Marcos, Mil Cumbres); Central Cuba: Ci (Sierra de Escambray: Pico San Juan); East Cuba: Gr, SC, Gu (Sierra Imías: Alto la Yamagua and Tres Piedras). Epiphytic; prefers shady places in montane rainforests and cloud forests from 900 to 1500 m, usually in vegetation on soils derived from volcanic rock. Scattered.

Variability: The collection Stenzel 888 is from vegetation on serpentine. These plants show a slightly different habitus, with the otherwise conspicuous spathe being reduced, dark purple colored flowers and other minor differences. However, unless more material from this area has been examined to evaluate the stability of these characteristics, it is not advisible to treat those populations as a separate subspecies.

Pleurothallis rubroviridis Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 327. 1858. ≡Acianthera rubroviridis (Lindl.) Pridgeon & M. W. Chase in Lindleyana 16: 246. 2001. Holotype: “in Cuba Orientali, 1856-7” [blue label], [Monte Verde, according to Wright in Lindley (1858)], Wright (K-L!).– Fig. 33.

=Pleurothallis cubensis Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 328. 1858. ≡Acianthera cubensis (Lindl.) Pridgeon & M. W. Chase in Lindleyana 16: 243. 2001. Lectotype (designated here): “in Cuba Orientali, 1856-7” [blue label], [Monte Verde, 28-IV, according to Wright in K-L], Wright 653 (K-L!; isolectotypes?: AMES No. 72363 [photo!], K!).

Herbs, subcaespitose, 6-20 cm high. Rhizome very short, separating the ramicauls by 2-3 mm, covered by three tubular sheaths. Ramicauls elongated, erect or ascending, rigid, laterally compressed, surcate, 4-14 cm long, basally 2-articulated, to ¼ covered by two conduplicate sheaths; without an annulus. Leaves coriaceous and rigid, narrow elliptic to oblanceolate, acute, minutely tridentate, 2-6 x 1-2 cm, yellowish green, glabrous; base cuneate; margin erose. Inflorescence a terminal raceme very short, 1-3(-4) per stem, 2-3 flowers, subtended at the base by a falcate sheath of 0,6-0,8 cm in length; peduncle erect, 0,3 cm long, with two bracts; axis 0,2-0,5 cm long. Pedicels 1 mm long, entirely fused with the axis; bract membranous, infundibuliform, often papillose, 2-3 mm long. Flowers resupinate or not, anthesis successive. Sepals thickened, yellowish green, basally mottled with purple, verrucate on the inner side and papillose externally; margin entire; dorsal sepal free, pandurate, obtuse to subacute, 3-veined, 6,2-6,6 x 1,2-1,4 mm; the lateral ones connate almost up to the tip, synsepal ovate, lengthwise folded, obtuse, bifid, 6-veined, 5,9-6,2 x 2,1-2,3 mm. Petals thickened, purple, narrow obovate, slightly falcate, obtuse to rounded, 1-veined, 2,5 x 1,1 mm; margin slightly crenulate in the upper part. Labellum slightly thickened, greenish, simple, oblong to narrow ovate, obtuse to rounded, 2,5 x 1,5 mm when expanded; upper side lengthwise surcate from base almost up to the tip, with two elongated calli in the middle, verrucate in el ¼ apical; base biauriculate, short clawed; margin slightly crenulate or serrate. Column yellowish, slightly curved inwards, 2 mm long; foot 0,5 mm long; clinandrum winged. Anther apical; pollinia 2, suborbicular, sculpture punctate. Stigma ventral. Ovary 1 mm long, papillose. Capsule 0,5 cm long, verrucate. – Fl.: III-VI, Fr.: III-VII.

Distribution: Venezuela (Foldats 1970), Cuba. Present in East Cuba: SC (Sierra de Cobre: Loma del Gato; Gran Piedra), Gu. Epiphytic; prefers humid and shady or open places in montane rainforests and secondary formations, mesophyllous evergreen rainforests from 800 to 1200 m, in vegetation on lateritic soil derived from limestone. Rare.

Variability: Regarding the overall plant size Pleurothallis rubroviridis varies considerably. These differences prompted Lindley to describe the species a second time within the same paper. Both descriptions are based on material collected by Charles Wright.


[page 58↓]

Fig. 33: Pleurothallis rubroviridis Lindl.

1 – Plant. 2 – Leaf, cross section. 3 –  Flower. 4+5 – Sepals. 6 – Petal. 7 – Lip. 8 – Lip, ovary and column in natural position.

Fig. 34: Pleurothallis ruscifolia (Jacq.) R. Br.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis ruscifolia (Jacq.) R. Br. in Aiton, Hortus Kew. 2. 5: 211. 1813. ≡Epidendrum ruscifolium Jacq., Enum. Syst. Pl. 29. 1760. ≡Dendrobium ruscifolium (Jacq.) Sw. in Nova Acta Regiae Soc. Sci. Upsal. 6: 84. 1799. Holotype: [drawing] “Ruscus? foliis solitariis lanceolato-ovatis” [based on material from Martinica?] in Burman, Pl. Amer. t. 176, f. 2. 1758. – .

Herbs, subcaespitose, 15-35 cm high. Rhizome very short, separating the ramicauls by 2-3 mm, covered by three tubular sheaths. Ramicaulselongated, 11-21 cm long, 2-articulated, below the middle partially covered by two tubular sheaths; without? an annulus. Leaves oblanceolate to narrow elliptic, acute to subacuminate, tridentate, 4-14 x 1-3,5 cm, green, glabrous; base attenuate; margin entire. Inflorescence a terminal multi-flowered fasciculum, subtended at the base by a suborbicular to broadly ovate and laterally compressed sheath of 0,4-0,6 cm in length. Pedicels up to 6 mm long, free; bract membranous, infundibuliform, up to 4 mm long. Flowers resupinate, anthesis successive or simultaneous. Sepals membranous, yellowish, carinate; margin entire; dorsal sepal free, lanceolate, slightly caudate, 3-veined, 6,5-7,5 x 2-2,1 mm; the lateral ones entirely connate, synsepal lanceolate, acute, 4-veined, 6,5-7,5 x 1,7-1,9 mm. Petals slightly thickened, yellowish, subulate, acute, 2-veined, 3,7-3,9 x 0,3-0,4 mm; margin minutely serrate. Labellum slightly thickened, whitish, ovate, apiculate, 1,5-1,6 x 0,9 mm when expanded; upper side basally with an orbicular papillose depression; base obtuse; margin membranous and antrorse below the middle, slightly sinuate in the upper portion. Column whitish, stout, slightly curved inwards, 0,8 mm long; foot reduced; clinandrum truncate; base with two calli. Anther apical; pollinia 2, oblong to claviform, sculpture psilate and lepanthiform. Stigma ventral. Ovary 1 mm long, glabrous. Capsule 5-8 mm long, ribbed. – Fl.: III-VIII, Fr.: VI-X.

Distribution: Tropical America from Costa Rica to Brazil and Bolivia, Antilles. Present in East Cuba: Gr , SC, Gu (Sierra de Imías: Alto Clavellinas). Epi- or lithophytic; in partially open places of gallery forests, montane rainforests and cloud forests, 400-1500 m. Rare.


[page 59↓]

Fig. 35: Pleurothallis sertularioides (Sw.) Spreng.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip. 6 – Lip, ovary and column in natural position.

Fig. 36: Pleurothallis shaferi Ames


1 – 
Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis sertularioides (Sw.) Spreng., Syst. Veg. 3: 731. 1826. ≡Epidendrum sertularioides Sw., Prodr.: 122. 1788. ≡Dendrobium sertularioides (Sw.) Sw. in Nova Acta Regiae Soc. Sci. Upsal. 6: 83. 1799. ≡Specklinia sertularioides (Sw.) Lindl., Gen. Sp. Orchid. Pl.: 8. 1830. ≡Anathallis sertularioides (Sw.) Pridgeon & M. W. Chase in Lindleyana 16: 250. 2001. Lectotype (Fawcett & Rendle 1910: 65, specified here): “Epidendrum sertularioides Swartz, Jamaica”, Swartz (BM No. 82293!; isolectotypes?: B ex herb. Willdenow 16895 [photo!], C [n.v.], G [n.v.], S [photo!], S ex herb. Alstroemer [photo!], W ex herb. Reichenbach Orch. No. 26610!). – .

Herbs, repent, 1,2-4,5 cm high. Rhizome elongated, separating the ramicauls by 0,2-0,5 cm, covered by three tubular sheath. Ramicauls very short, ascending, 0,2-0,4 cm long, basally articulated, entirely covered by a scarious sheath; annulus present. Leaves fleshy, oblanceolate to subspathulate, obtuse, minutely tridentate, 1-4 x 0,3-0,4 cm, yellowish green, glabrous; base narrow attenuate; margin entire. Inflorescence a terminal raceme, erect, solitary (rarely two) per stem, 1(-2) flowers, subtended at the base by an ovate sheath of ± 1 mm in length; peduncle capillary, erect, 0,8-1,5 cm long, basally with a bract; axis (in two-flowered inflorescences) capillary, straight, 0,5 cm long. Pedicels 3-5 mm long, free; bract membranous, infundibuliform, acute, 1,5-2 mm long. Flowers resupinate, anthesis successive, segments whitish and apically yellow. Sepals membranous and slightly rigid, carinate, 3-veined, acute; margin entire; dorsal sepal free, lanceolate, 4,9-5 x 1,1-1,2 mm; the lateral ones connate to 1 mm, sometimes adnate up to the middle, lanceolate to triangular, falcate, apically attenuate, 4,6-4,7 x 1,1-1,2 mm. Petals membranous, lanceolate or subulate, falcate, acute, 1-veined, 3,4-3,5 x 0,9-1 mm; margin entire. Labellum slightly thickened, simple, oblong to lanceolate, acute, 3 x 1 mm when expanded; upper side with an elongated depression in the middle; base abruptly attenuate, with two minute dentiform calli; margin antrorse-auriculate below the middle, apically minutely papillose and revolute. Column whitish, slightly curved inwards, [page 60↓]± 2 mm long; foot 0,5 mm long, with a shallow and ovate cavity; clinandrum winged with a serrate margin. Anther apical; pollinia 2, pyriform, laterally compressed, sculpture gemmate. Stigma ventral. Ovary 1,7-1,8 mm long, glabrous, surcate. Capsule 3-5 mm long, glabrous. – Fl.: V-X, Fr.: V-XI.

Distribution: Central America from México to Nicaragua (Luer 1975a), Greater Antilles (Jamaica and Cuba) and Trinidad[?]. Present in West Cuba: PR; Central Cuba: Ci (Sierra de Escambray; Matagua de la Vega), SS (Trinidad: Pico Potrerillo, Mogote Mi Retiro, Trinidad Mts. Habanilla Falls); East Cuba: Gr, Ho, SC, Gu. Epiphytic or lithophytic; prefers shady to open places in montane rainforests, mesophyllous evegreen rainforests, gallery forests and vegetation of the mogotes (occasionally in secondary forests too) from 200 to 1400 m. Common. Most frequent species of the genus in Cuba.

Pleurothallis shaferi Ames in Orchidaceae 7: 119. 1922 [as “schaferi”]. Lectotype (Nir 2000: 302): “Cuba, Sierra Nipe, near Woodfred”, 450-550 m, 05-I-1910, Shafer 3441 (AMES No. 21122!; isolectotype: NY No. 9214!). – Fig. 36.

Herbs, caespitose, 0,5-1,7 cm high. Rhizome reduced. Ramicauls very short, erect or ascending, 1-4 mm long, 3-articulated, entirely covered by three scarious, tubular or infundibuliform sheaths; annulus present. Leaves spathulate to oblanceolate, obtuse, minutely tridentate, 0,4-1,3 x 0,2-0,4 cm, thickened, green, glabrous; base attenuate; margin entire or minutely crenulate. Inflorescence a terminal raceme, erect, capillary, solitary (rarely two per stem), 3(or very rarely 4-5) flowers, subtended at the base by an ovate sheath of 0,9-1,2 mm in length; peduncle 0,3-1 cm long, with a basal bract; axis 0,2-0,8 cm long. Pedicel 1-1,8 mm long, fused basally with the axis; bract membranous, acute, 1 mm long. Flowers with simultaneous anthesis, segments membranous, whitish or greenish, apically yellowish. Sepals papillose-carinate; margin entire or minutely papillose; dorsal sepal basally connate with the lateral ones, narrow elliptic-ovate, acute, 3-veined, 2,5-3,2 x 1,1-1,2 mm; the lateral ones connate to 1 mm, the base forming a mentum with the ovary, lanceolate, falcate, acute, 1-veined, 2,4-3 x 0,9-1,1 mm. Petals spathulate, slightly falcate, obtuse to rounded, 1-veined, 1,4-1,6 x 0,6 mm; margin glabrous or slightly serrate in the upper part. Labellum simple, oblong, obtuse, 1,6-1,7 x 1,1 mm when expanded; upper side with an elongated depression in the central portion; base abruptly clawed; margin apically crenulate and revolute. Column whitish, slightly curved inwards, ± 1 mm long; foot 0,7-0,8 mm long, with an elongated cavity and two orbicular calli; clinandrum winged with a serrate margin. Anther apical; pollinia 2, obovate, sculpture psilate. Stigma ventral. Ovary 0,6 mm long, glabrous, surcate. Capsule 3-4 mm long, glabrous. – Fl.: III-VII, Fr.: III-VIII.

Distribution: Endemic in East Cuba: Ho, SC (Sierra del Cristal: headwaters of the Río Lebisa; Sierra Maestra: Pico Turquino; Sierra Cobre: Loma del Gato), Gu. Epiphytic; prefers humid places in montane rainforests and charrascales from 300 to 800 m, usually in vegetation on soils derived from serpentine. Scattered.

Variability: Populations in Guantánamo, which marks the eastern limit of its distribution, have larger flowers and inflorescences with 4(-5) flowers instead 3. This morphology shows similarities to Pleurothallis simpliciflora D.D.Dod from Hispaniola.

Pleurothallis testaefolia (Sw.) Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 328. 1858. ≡Epidendrum testaefolium Sw., Prodr.: 122. 1788. ≡Cymbidium testaefolium (Sw.) Sw. in Nova Acta Regiae Soc. Sci. Upsal. 6: 71. 1799. Lectotype (Nir 2000: 304, specified here): “Cymbidium testaefolium Swartz, Herb. Swartzii, Jamaica”, Swartz (S ex herb. Swartz [photo!]; isolectotypes?: B ex herb. Willdenow 16984 [photo!], BM No. 82277!, SBT [n.v.], W ex herb. Reichenbach Orch. No. 16036!). – Fig. 37.

Herbs, repent, prostrate. Rhizome elongated, separating the ramicauls by 0,5-1,5 cm long and covered by three conduplicate and carinate sheath. Ramicauls 3-7 mm long, basally 2-articulated, entirely covered by two scarious sheath, conduplicate and carinate; without an annulus. Leavesrigid, elliptic to suborbicular, prostrate, limb usually turned [page 61↓]upside down, obtuse, short acuminate, minutely tridentate, 1-3 x 0,7-1,5 cm, green, dotted with purple, glabrous, carinate; base short attenuate; margin entire. Inflorescence a terminal raceme, solitary, single flowered, subtended at the base by a conduplicate and serrate sheath of 3-6 mm in length; peduncle 2 mm long, with two or three bracts. Pedicels 1 mm long; bract membranous, tubular, up to 1 mm long. Sepals slightly thickened, purple, whitish-pubescent, convex, carinate; margin entire; dorsal sepal free, oblong, obtuse, 3-veined, 5-5,2 x 2,2-2,3 mm; the lateral ones connate almost up to the tip, synsepal broadly ovate, obtuse, apically bidentate, 6-veined, 5,9-6 x 5-5,4 mm. Petals membranous, hyaline, spathulate, obtuse to rounded, 1-veined, 2,4-2,6 x 1 mm; margin denticulate in the tip. Labellum slightly thickened and membranous, light reddish to purple, oblong, rounded, 4-4,2 x 2-2,3 mm when expanded; upper side with two verrucate calli in the middle, apically covered with minute, dentiform calli; base short cuneate-attenuate, biauriculate; margin serrate to fimbriate or lacerate. Column whitish, slender and curved inwards, 2,2 mm long; foot 0,6 mm long, with a elongated and shallow cavity; clinandrum distinctly winged, apically serrate. Anther apical; pollinia 2, obovate, sculpture rugulate to granulate. Stigma ventral. Ovary 1,5 mm long, papillose-pubescent. Capsule pubescent. – Fl.: II-IX, Fr.: II-X.

Distribution: (Sub)Tropical America from Honduras to Venezuela and Surinam (Foldats 1970), Greater Antilles (except Puerto Rico), Martinica. Present in East Cuba: Gr (Sierra Maestra: macizo of the Turquino, La Aguada de Joaquín), SC (Sierra Cobre: Loma del Gato). Epiphytic on trunks of trees; prefers shady places in montane rainforests or secondary forests, sometimes on cultivated fruit trees (Mangifera indica), from 1000 to 1400 m, in vegetation on soils derived from volcanic rock. Rare.

Reproduction biology: In the natural position the prostrate leaf exposes the lower side, while the upper one with the flowers are hidden on the substrate.

Fig. 37: Pleurothallis testaefolia (Sw.) Lindl.

1 – Plant with flower. 2+3 – Sepals. 4 – Petal. 5 – Lip. 6 – Lip, ovary and column in natural position.

Fig. 38: Pleurothallis tribuloides (Sw.) Lindl.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis tribuloides (Sw.) Lindl., Gen. Sp. Orchid. Pl.: 6. 1830. ≡Epidendrum tribuloides Sw., Prodr.: 123. 1788. ≡Dendrobium tribuloides (Sw.) Sw., Nova Acta Regiae Soc. Sci. Upsal. 6: 83. 1799. ≡Cryptophoranthus tribuloides (Sw.) H. Dietrich in Revista [page 62↓]Jard. Bot. Nac. Univ. Habana 5: 48. 1984. ≡Specklinia tribuloides (Sw.) Pridgeon & M. W. Chase in Lindleyana 16: 259. 2001. Lectotype (Fawcett & Rendle 1910: 62, specified here): “Epidendrum tribuloides Swartz, Jamaica”, Swartz (BM No. 82281!; isolectotypes?: B ex herb. Willdenow 16893 [photo!], G!, S [photo!], S ex herb. Alstroemer [photo!], W ex herb. Reichenbach Orch. No. 26480!). – .

=Pleurothallis spathulata A. Rich. & Galeotti in Ann. Sci. Nat., Bot., ser. 3, 3: 17. 1845. Lectotype (designated here): “Mexico, prés Jalapa, 4000 [pies?]”, XI-IV-1840, Galeotti 5181 (W ex herb. Reichenbach Orch. No. 12730!).

=Pleurothallis fallax Rchb. f. in Bonplandia (Hannover) 3: 224. 1855. Lectotype (designated here): “México”, Leibold 615 (W ex herb. Reichenbach Orch. No 24905!).

Herbs, caespitose, 3-5 cm high. Rhizome very short, ascending, separating the ramicauls by 0,5-1 mm, covered by two or three conduplicate and carinate sheaths. Ramicauls very short, 0,2-0,5 cm long, basally 1-articulated, entirely covered by a scarious and conduplicate sheath; annulus present. Leaves slightly coriaceous and fleshy, spathulate, obtuse to emarginate, tridentate, 3-4,5 x 0,5-1 cm, green, glabrous; base narrow attenuate; margin entire. Inflorescence a terminal raceme, solitary, with 1-3 flowers, basally covered by various sheaths; peduncle straight, 1-2 mm long, with two or three bracts; axis 1 mm long. Pedicels up to 4 mm long, free; bract scarious, conduplicate, acute, 5-7 mm long. Flowers resupinate, brick-colored, anthesis successive. Sepals thickened and rigid, carinate; margin papillose, covered in the upper part on both sides with minute warts (0,2 mm in diameter); dorsal sepal free but adnate to the lateral ones, panduriforme to (narrow) oblong, acute, 3-veined, 6,5-7,2 x 2,2-2,6 mm; the lateral ones connate almost up to the tip, the base forming a mentum with the ovary, synsepal oblong, slightly attenuate below the middle, acute to subobtuse, 6-veined, with minute papillae on the keels, 5,7-6,2 x 3-3,2 mm. Petals slightly thickened, spathulate, oblique in the upper part, acute, 2-veined, 2,6-2,7 x 1,1 mm; margin entire. Labellum slightly thickened, oblong, obtuse to rounded, 2,5 x 1,1 mm when expanded; upper side in the middle with two less distinct calli, apically papillose; base truncate; margin apically crenulate or papillose. Column thick, slightly curved inwards, 2 mm long; foot 1,5 mm long, with a elongated cavity; clinandrum winged and bidentate. Anther apical; pollinia 2, pyriform, laterally compressed, sculpture granulate. Stigma ventral. Ovary 1 mm long, densely papillose. Capsule 0,5 cm long, echinate. – Fl.: III-X, Fr.: III-XI.

Distribution: Tropical America from México to Pánama and Surinam (Luer 1975b), Greater Antilles (Cuba, Jamaica). Present in West Cuba: PR; Central Cuba: SS, (Trinidad Mts. Habanilla Falls, S.Clara, Pitajones to Ciegos Ponciano; Banao, Yayabo River); East Cuba: Gr, Ho, SC, Gu. Epiphytic or lithophytic; prefers shady or partially open places in vegetation of the mogotes, mesophyllous evergreen rainforests, montane rainforests, gallery forests; in secondary forests (cupeyales) too, from 200 to 1000 m, usually on limestone. Common.

Ecology: Frequently in association with Pleurothallis sertularioides, Pleurothallis tribuloides and Pleurothallis wilsonii.

Pleurothallis trichophora Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 326. 1858. Lectotype (Luer 2000: 48, specified here): “in Cuba Orientali, 1856-7” [blue label], [summit of Loma del Gato, according to Wright in Lindley (1858)], Wright 659 (K-L!; isolectotypes?: AMES No. 72414 [photo!], BR No. 843534!, G ex herb. Barbey-Boissier!, K!).– Fig. 39.

Herbs, caespitose, 3-8 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls ascending to pendent, 1,5-3,5 cm long, up to the middle 4-articulated, surcate, to 2/3 covered by 4 scarious, conduplicate and carinate sheaths; without an annulus. Leaves coriaceous, narrow elliptic-lanceolate, acute, 1,5-4,5 x 0,8-1 cm, green to greyish green and slightly rough on the upper side, green on the lower side; base acute; margin denticulate and erose. Inflorescence a terminal raceme, slightly pendent, [page 63↓](1-)2-5(-8) per stem, 2-15-flowered, subtended at the base by a conduplicate sheath of 2-9 mm in length; peduncle 1-6 cm long, with a bract; axis 2-14 long. Pedicels (3-)4 mm long, free; bract membranous, conduplicate, acute to apiculate, 2(-3) mm long. Flowers resupinate, but in pendent inflorescences apparently not, anthesis successive. Sepals membranous, slightly thickened along the nerves, purple with yellow tips, 3-veined, carinate; dorsal sepal connate basally up to 0,8 mm with the lateral ones, lanceolate, acute, 6 x 1,8 mm; margin entire or slightly crenulate in the upper part; the lateral ones adnate up to the middle, the base forming a mentum with the ovary, narrow ovate, falcate, slightly caudate, 6 x 2 mm; margin entire. Petals membranous, hyaline, narrow spathulate, apically subulate or subcaudate, 1-veined, 5 x 1 mm; margin entire. Labellum membranous, purple, suborbicular to obtuse-cordifome, rounded, 3 x 2 mm when expanded; upper side with two lengthwise calli bordering a central depression; base clawed; margin in the middle with two small antrorse lobes, apically denticulate. Column whitish or light reddish, slender and curved inwards, 3 mm long; foot 1 mm long; clinandrum winged and denticulate. Anther apical; pollinia 2, triangular, sculpture punctate to vermicular-fossulate. Stigma ventral. Ovary 2 mm long, papillose and verrucate. Capsule verrucate. – Fl. and Fr.: II-IV?.

Distribution: Endemic in Central Cuba: Ci (Sierra de Escambray), SS (Trinidad: Pico Potrerillo, Finca El Avión); East Cuba: Gr (Victorino: Loma El Gigante), SC (Sierra Cobre: Loma del Gato; Loma Redonda, Sevilla). Epiphytic; prefers shady or partially open places in montane rainforests from 900 to 1200 m. Very rare.

Fig. 39: Pleurothallis trichophora Lindl.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 40: Pleurothallis trichyphis Rchb. f.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Pleurothallis trichyphis Rchb. f. in Flora 48: 276. 1865. Lectotype (designated here): “Cuba, 1860-1864”, Wright 3345 p.p. (K!; isolectotypes?: AMES No. 72415 [photo!], BM No. 82343!, G ex herb. Barbey-Boissier!, G ex herb. de Candolle!, GOET!).– .

Herbs, caespitose, 0,8-1,5 cm high (excluding the inflorescence). Rhizome reduced. Ramicauls very short, 0,5-1,5 mm long, 3-articulated, entirely covered by three scarious and tubular sheaths; annulus present. Leaves slightly thickened, oblanceolate to subspathulate, acute and short apiculate, 0,4-1,3 x 1,5-3 mm, green, glabrous; base [page 64↓]attenuate; margin entire or minutely erose above. Inflorescence a terminal raceme, solitary, few-flowered, subtended at the base by a tubular sheath of 0,5 mm in length; peduncle erect, 0,8-2,6(-3,5) cm long, with two bracts; axis congested, 0,2-0,5 cm long. Pedicels 1-3,5 mm long, free; bract membranous, acute, 1-2 mm long. Flowers resupinate, anthesis successive. Sepals membranous, yellow, slightly carinate, acute; margin entire; dorsal sepal connate to 0,5 mm with the lateral ones, lanceolate to narrow elliptic, 3-veined, 2,6-3,8 x 1,1-1,2 mm; the lateral ones connate almost up to the tip, the base forming a mentum with the ovary, synsepal ovate to triangular, bifid, 4-veined, 2,6-3,8 x 2-2,2 mm. Petals membranous, hyaline, spathulate, obtuse to rounded, 1-veined, 1-1,2 x 0,4 mm; margin apically denticulate. Labellum membranous, yellowish, oblong, obtuse to emarginate, 1,6-1,8 x 0,7 mm when expanded; base truncate; margin antrorse below the middle. Column whitish, slightly curved inwards, 1 mm long; foot 0,7 mm long, with an elongated cavity and two orbicular calli; clinandrum winged, glabrous. Anther apical; pollinia 2, triangular, sculpture psilate to slightly rugulate. Stigma ventral. Ovary 0,6 mm long, glabrous. Capsule 2 mm long, glabrous. – Fl.: VIII, Fr.: VIII-IX.

Distribution: Endemic in East Cuba: Gr (Guisa: Victorino), Gu (Sierra Imías: Loma Maestra la Yamagua). Epiphytic; prefers partially shaded places in humid mogote vegetation and mesophyllous evegreen rainforests from 400 to 800 m, in vegetation on limestone. Very rare.

Pleurothallis wilsonii Lindl. in Ann. Mag. Nat. Hist., ser. 3, 1: 326. 1858. ≡Acianthera wilsonii (Lindl.) Pridgeon & M. W. Chase in Lindleyana 16: 247. 2001. Lectotype (Fawcett & Rendle 1909b: 129): “Pleurothallis wilsonii m.; Jamaica”, Wilson ex herb. Hooker (K!).
Fig. 41.

=Pleurothallis confusa Fawc. & Rendle in J. Bot. 47: 129. 1909. Lectotype (designated here): “in Cuba Orientali, 1856-7” [blue label], [Sta. Isabel, according to Wright in Lindley (1858)], Wright 668 (K-L!).

Herbs, repent, 4-9 cm high. Rhizome elongated, separating the ramicauls by up to 1,3 cm, covered by three scarious and brown sheaths. Ramicauls elongated, slender, ascending, 2-5 cm long, basally 2-articulated, up to the middle covered by two scarious, carinate sheaths; without an annulus. Leaves coriaceous, lanceolate to (narrow) elliptic, acute, tridentate, 2-4 x 0,8-1 cm, green, glabrous; base obtuse to subacute; margin entire. Inflorescence a terminal raceme, 1-5 per stem, 1(-2) flowers, subtended at the base by a conduplicate sheath of 2-4 mm in length; peduncle ascending, 2-5 mm long, without a bract; axis (en two-flowered inflorescences) 2 mm long. Pedicels 0,6 mm long, fused up to ¾ with the axis; bract membranous, infundibuliform, 1,3-1,5 mm long. Flowers resupinate, anthesis successive. Sepals membranous or slightly thickened, yellowish and reddish, carinate; margin entire; dorsal sepal free, narrow oblong, acute to subobtuse, 3-veined, 4-4,3 x 1,4-1,5 mm; the lateral ones entirely connate, the base forming a mentum with the ovary, synsepal ovate, obtuse to subacute, 6-veined, 3,9-4,1 x 2,8-3,2 mm. Petals slightly thickened, whitish, spathulate, acute, 1-veined, 2,5 x 0,9 mm; margin apically serrate. Labellum slightly thickened, oblong, narrow ovate or slightly trilobate, obtuse to rounded, 2,6-2,9 x 1,5-1,6 mm when expanded; upper side in the cantral portion with two elongated calli; base broadly cuneate, auriculate; margin basally antrorse, serrate and denticulate. Column whitish, slightly curved inwards and winged, 1,7-1,9 mm long; foot 0,8 mm long, with an elongated, shallow cavity; clinandrum dentate. Anther apical; pollinia 2, amorphous, sculpture irregular. Stigma ventral. Ovary 1,5-1,8 mm long, glabrous. Capsule 8-10 mm long, ribbed. – Fl.: IV-VIII, Fr.: IV-IX.

Distribution: Venezuela (Foldats 1970); Greater Antilles, Domínica and Guadalupe. Present in Central Cuba: SS (Cordillera Banao); East Cuba: Gr, Ho, SC, Gu. Epiphytic or Lithophytic; prefers partially open places in vegetation of the mogotes and mesophyllous evergreen rainforests from 300 to 600 m, usually on limestone. Scattered.

Reproduction biology: Probably this species shows auto- or cleistogamy, since the majority of the flowers set fruit without opening. The pollen morphology [page 65↓](amorphous pollinia with no defined surface) backs this suggestion.

Fig. 41: Pleurothallis wilsonii Lindl.

1 – Plant. 2+3 – Sepals. 4 – Petal. 5 – Lip.
6 – Lip, ovary and column in natural position.

Fig. 42: Pleurothallis wrightii Rchb. f.

1 – Plant. 2 – Leaf, cross section. 3+4 – Sepals. 5 – Petal. 6 – Lip. 7 – Lip, ovary and column in natural position.

Pleurothallis wrightii Rchb. f. in Flora 48: 276. 1865. Lectotype (designated here): “Cuba, Wright 1509”, Wright “1509” (W ex herb. Reichenbach Orch. No. 13015!).– .

=Pleurothallis lichenicola Griseb., Cat. Pl. Cub.: 259. 1866. ≡Specklinia lichenicola (Griseb.) Pridgeon & M. W. Chase in Lindleyana 16: 258. 2001. Lectotype (designated here): “prope villam Monte Verde dictam, Cuba Orientali, Jan.-Jul. 1959”, [Monte Verde, 3-XII, according to Wright in AMES], Wright 1507 (GOET!; isolectotypes?: AMES No. 72371 [photo!], K!, K-L!).

=Pleurothallis richteri H. Dietr. in Orchidee (Hamburg) 35: 223. 1984. Holotype: “Cuba, Guantánamo, Baracoa, Vega de la Palma, alrededores del Río Duaba”, Bisse & al. (HAJB No. 39729!).

Herbs, subrepent, 0,5-1,3 cm high. Rhizome very short, separating the ramicauls by < 0,5 mm, covered by two membranous sheaths. Ramicauls very short, ascending, 1-2,5 mm long, 3-articulated, entirely covered by three membranous and tubular sheaths; annulus present. Leaves thickened, elliptic to obovate or suborbicular, obtuse to rounded, minutely tridentate, 4-10 x 1,5-3 mm, green to greenish purple, usually laxamente diminutely verrucuate on both sides; base short attenuate; margin entire. Inflorescence a terminal raceme, (1-)2-3 per stem, generally single flowered, subtended at the base by a tubular sheath of 0,5 mm in length; peduncle capilar, erect, glabrous, 2-3 mm long, with a bract. Pedicels up to 1 mm long, free; bract membranous, infundibuliform, up to 0,8 mm long. Flowers resupinate. Sepals slightly thickened, light reddish purple, somewhat carinate, narrow ovate to elliptic, apically thickened, cucullate and slightly recurved; margin entire; dorsal sepal connate to 0,8 mm with the lateral ones, narrow ovate, 3-veined, 2,4-3 x 1,1-1,3 mm; the lateral ones connate basally up to 1 mm, forming a mentum with the tip of the ovary , 2-veined, 2,5-3 x 1-1,2 mm. Petals membranous, white or slightly light reddish, spathulate, obtuse to rounded, 1-veined, 1,4-1,7 x 0,5 mm; margin entire. Labellum slightly thickened, dark purple, simple, oblong to panduriforme, slightly [page 66↓]recurved, acute to obtuse, 1,6-1,9 x 0,5-0,8 mm when expanded; upper side with a central depression; base obtuse, abruptamente clawed; margin basally papillose, apically revolute. Column whitish, slender, almost erect, 1,4 mm long; foot 0,6 mm long, with an elongated cavity, two orbicular calli and a papillose base; clinandrum serrate. Anther apical; pollinia 2, lentiform to obtuse triangular, sculpture psilate. Stigma ventral. Ovary 0,8 mm long, glabrous, purple. Capsule 2,5-3,5 mm long, glabrous. – Fl.: III-VI, Fr.: III-VII.

Distribution: Endemic in East Cuba: Ho, SC (Sierra del Cristal; Sierra de Cobre: Loma del Gato; Turquino massif: Pico Cardero), Gu (Vega la Palma: banks of the Río Duaba; Maisí: banks of the Arroyo Yarey). Epiphytic; prefers humid and shady places in montane rainforests, mesophyllous evergreen rainforests, gallery forests and charrascales from 300 to 900 m, usually in vegetation on soils derived from serpentine. Scattered.

Variability: The plants from the South of Oriente (Sierra Maestra) have smooth instead of verrucate leaves.

3.2 


[page 67↓]

3.3  Reproductive biology

There was only one observation of potentially pollinating insects during the whole field work. A specimen of the dipterian genus Drosophila was observed visiting Pleurothallis ‘flabelliformis’. The insect entered the flower several times, but no pollinia were removed (Stenzel 2001).

Empirical data from observations in the field concerning anthesis and fruit set is presented in Tab. 5. The taxa included in this list comprise the whole subtribe in Cuba.


[page 68↓]

Tab. 5: Observations on anthesis and fruit set in pleurothallid genera.

Taxon

Amorphous pollinia with degenerated surface

Irregular fruit set after anthesis

Complete fruit set after anthesis

Complete fruit set without anthesis

Barbosella dussii (Cogn.) Dod

x

+?

+?

 

Brachionidium parvum Cogn.

+

  

+*

Lepanthes spp.

 

+

  

Lepanthopsis anthoctenium (Rchb. f.) Ames

x

   

Lepanthopsis melanantha (Rchb. f.) Ames

  

+?

 

Lepanthopsis microlepanthes (Griseb.) Ames

 

+

  

Lepanthopsis pygmaea C. Schweinf.

 

+

  

Octomeria ventii H. Dietrich

x

+

  

Platystele ovalifolia (Focke) Garay & Dunsterv.

+

  

+

Platystele hyalina H. Stenzel

 

+

  

Pleurothallis appendiculata Cogn.

x

+?

  

Pleurothallis aristata Hooker

 

+

  

Pleurothallis bissei Luer

 

+

  

Pleurothallis brighamii S. Wats.

+/-

+

  

Pleurothallis caymanensis C.D.Adams

x

+

  

Pleurothallis corniculata (Sw.) Lindl.

+

 

+

+1

Pleurothallis denticulata Cogn.

 

+

  

Pleurothallis domingensis Cogn.

+/-

 

+

+

Pleurothallis ekmanii Schltr.

 

+

  

Pleurothallis excentrica (Luer) Luer

 

+

  

Pleurothallisflabelliformis’ H. Stenzel

 

+

  

Pleurothallis gelida Lindl.

 

+

  

Pleurothallis gemina H. Stenzel

 

+

  

Pleurothallis ghiesbreghtiana A. Rich. & Galeotti

 

+

+2

 

Pleurothallis grisebachiana Cogn.

 

+

  

Pleurothallis helenae Fawc. & Rendle

+

  

+

Pleurothallis llamachoi Luer

 

+

  

Pleurothallis longilabris Lindl.

 

+

  

Pleurothallis mucronata Lindl. ex. Cogn.

 

+

  

Pleurothallis murex Rchb. f.

 

+

  

Pleurothallis nummularia Rchb. f.

?

+?

  

Pleurothallis obliquipetala Acuña & C. Schweinf.

 

+

  

Pleurothallis obovata (Lindl.) Lindl.

 

+

  

Pleurothallis odontotepala Rchb. f.

  

+

 

Pleurothallis oricola H.Stenzel

x

   

Pleurothallis papulifolia Luer

 

+

  

Pleurothallis prostrata Lindl.

 

+

  

Pleurothallis pruinosa Lindl.

+

  

+

Pleurothallis racemiflora (Sw.) Lindl.

 

+

  

Pleurothallis rubroviridis Lindl.

 

+

  

Pleurothallis ruscifolia (Jacq.) R. Br.

+

 

+

 

Pleurothallis sertularioides (Sw.) Spreng.

 

+

  

Pleurothallis shaferi Ames

 

+

  

Pleurothallis testaefolia (Sw.) Lindl.

 

+

  

Pleurothallis tribuloides (Sw.) Lindl.

 

+?

  

Pleurothallis trichophora Lindl.

 

+

  

Pleurothallis trichyphis Rchb. f.

 

+

  

Pleurothallis wilsonii Lindl.

+/-

+

+

 

Pleurothallis wrightii Rchb. f.

 

+

  

Trichosalpinx dura (Lindl.) Luer

 

x

  

Zootrophion atropurpureum (Lindl.) Luer

 

+

  

x – no observations; * – information was obtained from material elsewhere in the Antilles; ? – information questionable because of limited data). The Cuban species of Lepanthes were entirely uniform regarding the open flowers and irregular fruit set.

3.4  Palynology

Description of pollen morphology

Details of the pollen morphology of each taxon examined are given in the following. Figures are included in the CD-ROM attached to the back cover of this thesis. They can be viewed with the program REMview.exe on the CD. Comparative results are presented subsequently.

Arpophyllum giganteum Hartw. ex Lindl.: Eight pollinia, 500x220 µm, asymmetrically claviform, caudicles distinct, tetrads with a tendency to level off, sculpture irregularily punctate granulate.

Brachionidium parvum Cogn.: Four pollinia, ca. 300x250 µm, pyriform to clavate (?), fused with the tapetum, sculpture irregular. Pollinia could not be removed entirely from the anther tissue.

Dilomilis elata (Benth. & Hook.) Summerhayes: Eightpollinia, 300-500x300 µm, irregularily lenti- to pyriform, caudicles of tetrads loosely attached to each other, surface aciantheroid, sculpture psilate.

Lepanthes diaziae Luer: Two pollinia, 310x100 µm, elongate clavate, caudicles elaborate elongate, firm, surface lepanthoid, sculpture psilate.

Lepanthes dorsalis Schltr.: Two pollinia, 400-500x100-150 µm, elongate clavate, caudicles elaborate elongate, firm, surface lepanthoid, sculpture granulate to punctate.

Lepanthes dressleri Hesp.: Two pollinia, 400-500x100-150 µm, claviform, caudicles elongate, firm, surface lepanthoid, sculpture punctate to granulate

Lepanthes fulva Lindl.: Two pollinia, 350x80 µm, caudicles elongate, firm, surface lepanthoid, sculpture punctate.

Lepanthes melanocaulon Schltr.: Two pollinia, 400-450x100-120 µm, caudicles elongate, firm, surface lepanthoid, sculpture psilate.

Lepanthes obliquilobia Hesp.: Two pollinia, 420-500x100-120 µm, caudicles elongate, firm, surface lepanthoid, sculpture psilate to punctate.

Lepanthes silvae H. Dietrich: Four pollinia, a normally sized and shaped pair (350-400x70 µm, caudicles elongate, surface lepanthoid, sculpture psilate to punctate) and a reduced pair (150-200x50-90 µm, claviform, no caudicles, sporoderm collapsed, sculpture irregular).

Lepanthes trichodactyla Lindl.: Two pollinia, 400-500x200 µm, claviform, caudicles [page 69↓]capillary, short, surface lepanthoid (Stenzel 072) or less levelled (Stenzel 447), sculpture psilate.

Lepanthes turquinoensis Schltr.: Two pollinia, 500-550x100 µm, claviform, caudicles elongate, capillary, surface lepanthoid, sculpture perfectly psilate.

Lepanthopsis microLepanthes (Griseb.) Ames: Two pollinia, 220x100 µm, claviform, caudicles elaborate, elongate, surface lepanthoid, sculpture psilate (Stenzel 2000).

Lepanthopsis pygmaea C. Schweinf.: Two pollinia, 60-80 µm in diameter, sublentiform to hemispherical, caudicles absent, sculpture octomerioid with gemmate flanks.

Platystele hyalina H. Stenzel: Two pollinia, 350-400 µm, elongate clavate, caudicles long, firm, surface lepanthoid, sculpture punctate.

Platystele ovalifolia (Focke) Garay & Dunsterv.: Pollinia not removable.

Pleurothallis alpestris (Sw.) Lindl.: Two pollinia, 150 µm in diameter, angular lentiform, caudicles absent, sculpture punctate.

Pleurothallis appendiculata Cogn.: Two pollinia, 400x300 µm, obtuse-triangular to suborbicular, caudicles absent, sculpture granulate.

Pleurothallis aristata Hooker: Two pollinia, 250x180 µm, obliquely pyriform, laterally flattened, caudicles present, outer tetrads well separated (Puerto Rico) or with partially levelled edges (Suriname), sculpture punctate (Puerto Rico) or psilate (Suriname).

Pleurothallis bissei Luer: Two pollinia, ±300 µm in diameter, lentiform to obtusely triangular, caudicles absent, sculpture granulate.

Pleurothallis brighamii S. Wats.: Two pollinia, 350x200 µm, obovate to pyriform in outline, laterally flattened, caudicles elaborately ribbon-shaped, sculpture punctate to granulate.

Pleurothallis claudii D.D.Dod: Two pollinia, 400-450x200 µm, asymmetrically pyriform with indistinct caudicles, surface with levelled tetrads, sculpture psilate to punctate.

Pleurothallis cordatifolia D.D.Dod: Two pollinia, 400x280 µm, broadly triangular to subreniform, caudicles indistinct, sculpture psilate.

Pleurothallis corniculata (Sw.) Lindl.: Two pollinia, a) in presumably cleistogamous flowers amorphous, 700 µm long, exinous layer fragile and collapsed, sculpture reduced and irregular 4031, 4131-32; b) in open flowers (presumably xenogamous), oblong to obovate, 400x150 µm, caudicles distinctly ribbon-shaped, sculpture granular.

Pleurothallis curtisii D.D.Dod: Two pollinia, 450x190 µm, pyriform with elongate ribbon-like caudicles, sculpture psilate with a tendency to octomerioid patterns.

Pleurothallis delicatula Lindl.: Two pollinia, 200-250x100 µm, piri- to claviform, caudicles the tapering ends of the pollinia, indistinct, sculpture psilate.

Pleurothallis denticulata Cogn.: Two pollinia, 200-250 µm in diameter, obtusely triangular, caudicles rudimentary of loose tetrads, sculpture punctate to granulate.

Pleurothallis domingensis Cogn.: Two pollinia, 150-200 µm in diameter, suborbicular to triangular or amorphous (Stenzel 662), caudicles rudimentary, sculpture psilate octomerioid or indistinct (Stenzel 662).

Pleurothallis ekmanii Schltr.: Pollinia 8, 130-180 µm long, short claviform, caudicles of loose tetrads at the tapering end, sculpture perforate, punctate to fossulate.

Pleurothallis excentrica (Luer) Luer: Pollinia 8, 160-200x80-100 µm, cone-shaped, caudicles of loose tetrads at the tapering end of the pollinium, sculpture psilate.

Pleurothallisflabelliformis’ H. Stenzel: Pollinia 8, 200-250x80-110 µm long, coni- to [page 70↓]claviform, caudicles of loose tetrads at the tapering end of the pollinium, sculpture psilate.

Pleurothallis formondii D.D.Dod: Two pollinia, 250x150 µm, angular lentiform with short distinct caudicles, sculpture psilate with the edges of the tetrads partially fused or covered by an unknown layer.

Pleurothallis gelida Lindl.: Two pollinia, 200-250 µm in diameter, broadly ovate to sublentiform, caudicles very short, sculpture granulate to pregemmate.

Pleurothallis gemina H. Stenzel: Two pollinia, 170-200x100 µm, obliquely reni- to lentiform, sculpture psilate to punctate with a tendency to level tetrads.

Pleurothallis ghiesbreghtiana A. Rich. & Galeotti: Two pollinia, 350-400x250-260 µm, pyriform to obtusely triangular, laterally flattened, caudicles of loosely attached tetrads at the tapering end of the pollinium, sometimes with distinct threads of elastoviscin (fig. 6751), surface aciantheroid, sculpture varying psilate (Loddiges, Jamaica), punctate (Stenzel 967 from Puerto Rico, Stenzel 1298 from Cuba, Sandoval from El Salvador) to reticulate (Hort. Kew. 1999-2869 from Ecuador) or octomerioid (Hinton from Mexico, Marshal from Nicaragua, Hort Kew. 1968-22804 from Nicaragua).

Pleurothallis grisebachiana Cogn.: Two pollinia, 280-320x130-200 µm, claviform, laterally flattened, caudicles usually ribbon-like (fig. 6983) sculpture variably psilate, granulate or subgemmate.

Pleurothallis grobyi Batem. ex. Lindl.: Two pollinia, 250x140µm, sublentiform with short distinct stalky caudicles, sculpture octomerioid to gemmate.

Pleurothallis haitiensis D.D.Dod: Two pollinia, 300x120 µm, elliptical to slightly pyriform, caudicles indistinctly formed by the tapering ends of the pollinia, sculpture psilate or partially irregular. 8121-22. Two pollinia 220x150 µm, lentiform with short distinct caudicles, sculpture psilate to slightly punctate or granulate.

Pleurothallis helenae Fawc. & Rendle: Pollinia could not be removed, since they were in all stadiums neatly fused with the anther tissue (tapetum).

Pleurothallis hirsutula Fawc. & Rendle: Two pollinia, 250 µm in diameter, caudicles absent or consisting of a few tetrads loosely attached to each other, sculpture psilate to punctate or subgranulate.

Pleurothallis lanceola (Sw.) Lindl.: Two pollinia, 350-400x150-200 µm, caudicles in form of the tapering ends of the clavi- to coniform, laterally flattened pollinia, surface ± lepanthoid, sculpture punctate.

Pleurothallis laxa (Sw.) Lindl.: Two pollinia, ±200 µm in diameter, angular lentiform, caudicles absent, sculpture punctate to fossulato-granulate.

Pleurothallis llamachoi Luer: Two pollinia, 300x100 µm, claviform to coniform, caudicles indistinctly consisting of loose tetrads at the tapering end of the pollinium, sculpture psilate

Pleurothallis longilabris Lindl.: Two pollinia, 350x100 µm, slender, claviform, caudicles elongate, sculpture psilate.

Pleurothallis miguelii Schltr.: Two pollinia, 200-220 µm in diameter, angular lentiform, caudicles absent or of loosely grouped tetrads, sculpture punctate (fossulate).

Pleurothallis mitchellii D.D.Dod: Two pollinia, 320x120 µm, clavi- to pyriform, laterally flattened, caudicles formed by the tapering ends of the pollinia, sculpture psilate to slightly octomerioid.

Pleurothallis mucronata Lindl. ex. Cogn.: Two pollinia, 150x120 µm, obtusely triangular in outline, laterally flattened, sculpture psilate to granulate.

Pleurothallis murex Rchb. f.: Two pollinia, 110-150 µm in diameter, suborbicular [page 71↓](hemispherical), caudicles absent, sculpture vermiculato-fossulate to granulate

Pleurothallis obliquipetala Acuña & C. Schweinf.: Two pollinia, 300x90 µm, claviform, caudicles elongate, sculpture psilate.

Pleurothallis obovata (Lindl.) Lindl.: Two pollinia, 350x200 µm, pyriform, caudicles distinct, sculpture gemmate.

Pleurothallis odontotepala Rchb. f.: Two pollinia, 80-100 µm in diameter, obtusely triangular to suborbicular (hemispherical), laterally flattened, caudicles extremely reduced, sculpture granulate. .

Pleurothallis papulifolia Luer: Two pollinia, 280x180 µm, obovate, caudicles indistinct, sculpture punctate to fossulate. .

Pleurothallis prostrata Lindl.: Two pollinia, 300x220 µm, obtusely triangular to broadly reniform, caudicles indistinct, sculpture punctate to granulate. .

Pleurothallis pruinosa Lindl.: Pollinia of Cuban material could not be removed, since they were neatly fused with the anther tissue (tapetum) regardles which stage of development they were in. Type material from Surinam (Splitgerber 527): Two pollinia, 200-220x150-170 µm, pyriform, laterally flattened, caudicles distinct, surface lepanthoid, sculpture psilate. Material from Costa Rica was slightly longer (250x120 µm) with a perfectly lepanthiform surface. .

Pleurothallis pubescens Lindl.: Two pollinia, ±280 µm in diameter, angular lentiform, caudicles absent, sculpture vermiculato-fossulate .

Pleurothallis quisqueana D.D.Dod: Two pollinia, obtusely triangular in outline to angular lentiform, caudicles absent or indistinct, sculpture punctate.

Pleurothallis racemiflora (Sw.) Lindl.: Stenzel 643: two pollinia, 250x180 µm, obovate in outline, laterally flattened, caudicles indistinctly short, sculpture octomerioid. Stenzel 888: two pollinia, 300x210 µm, obovate in outline, laterally flattened, caudicles a loose agglomeration of tetrads, sculpture granulate.

Pleurothallis rubroviridis Lindl.: Two pollinia, 280x220 µm, suborbicular (hemispherical) to broadly ellipsoid in outline, laterally flattened, caudicles absent, sculpture punctate. .

Pleurothallis ruscifolia (Jacq.) R. Br.: No material from Cuba could be examined. Horich s.n. (Costa Rica) and an unvouchered specimen: two pollinia, 300x180 µm, coni- to claviform, surface lepanthoid, sculpture psilate. Material from the Antillean resisted preparation. The residues showed at best remnants of the typical lepanthoid sculpture type (Stenzel 2004b).

Pleurothallis shaferi Ames: Two pollinia, 200x110 µm, pyriform, laterally flattened, caudicles small and slender, sculpture psilate.

Pleurothallis sertularioides (Sw.) Spreng.: Two pollinia, 300x140 µm, pyriform, laterally compressed, caudicle a distinct flat stalky structure, sculpture gemmate.

Pleurothallis simpliciflora D.D.Dod: Two pollinia, 230x150 µm, lentiform with one end abruptly tapering into the short but distinct caudicle, sculpture ± psilate.

Pleurothallis testaefolia (Sw.) Lindl.: Two pollinia, 240x180 µm, broadly reniform, caudicles reduced, sculpture rugulate to granulate

Pleurothallis tribuloides (Sw.) Lindl.: Two pollinia, 350x190 µm, pyriform, laterally compressed, caudicle a short but distinct ribbon-shaped structure, sculpture granulate

Pleurothallis trichophora Lindl.: Two pollinia, 210x150 µm, triangular to broadly reniform, laterally flattened, caudicles absent or few loosely packed tetrads, sculpture punctate to vermicular-fossulate.


[page 72↓]

Pleurothallis trichyphis Rchb. f.: Two pollinia, 140x90 µm, obliquely pyriform to triangular, laterally flattened, caudicles indistinct tapering ends of the pollinia, sculpture psilate to slightly asper.

Pleurothallis velaticaulis Rchb. f.: Two pollinia, 140-200 µm in diameter, obtusely triangular to angular lentiform, caudicles absent, sculpture octomerioid.

Pleurothallis wilsonii Lindl.: Two pollinia, 220x140 µm, asimmetrically elliptical, caudicles reduced, sculpture punctate or fossulate to rugulate.

Pleurothallis wrightii Rchb. f.: Two pollinia, 110x80 µm, sublentiform to pyriform, laterally flattened, sculpture psilate to punctate with a tendency to smooth and level tetrad edges.

Stelis pygmaea Cogn.: Two pollinia, 210x100 µm, claviform, caudicles elongate, sculpture gemmate octomerioid.

Trichosalpinx dura (Lindl.) Luer: Two pollinia, 200x100 µm, coniform, caudicular end tapering, sculpture reticulate octomerioid.

Zootrophion atropurpureum (Lindl.) Luer: Two pollinia, 350x220 µm, lentiform with the caudicular end slightly elongate, sculpture psilate octomerioid (reticulate edge).

Atypical pollinia

The following species of Cuban pleurothallids did not render any examinable pollen material:

The pollinia of these species were often firmly attached to the tapetum and were of amorphous texture. The surface, if accessible, showed an irregularily collapsed sculpture.

General types of pollen characteristics

Antillean species of Pleurothallis shows the whole set of pollen morphological patterns found elsewhere in the subtribe, as was found already by Stenzel (2000). Antillean material of the other pleurothallid genera show the the palynological traits, that had been found to be characteristic for the respective genus in earlier studies (Schill & Pfeiffer 1977, Zavada 1990, Stenzel 2000). Fig. 43 and Fig. 44 provide a survey of the palynological variety found.


[page 73↓]

Most pollinia are laterally flattened on one side, i.e. they are ± circular in cross-section as unit (Fig. 43b). Caudicles may be absent (Fig. 43a), consist of loose tetrads (Fig. 43d), held together by threads of elastoviscin (Fig. 43h), or may be firm structures (Fig. 43e,f,g), usually forming the tapering end of a pollinium.

Fig. 43: Types of shape of pollinia in Cuban pleurothallids.

a – hemispherical, no caudicles (Pleurothallis murex); b – lentiform, caudicles of loosely aggregated tetrads (Zootrophion atropurpureum); c – obtusely triangular, reduced caudicles (Pleurothallis trichophora); d – irregular subpyriform, caudicles of loosely attached tetrads (Pleurothallis ekmanii, only 6 of the 8 tetrads shown); e – coniform, caudicles tapering (Pleurothallis grisebachiana); f – elongate claviform, caudicles stalky (Lepanthes dressleri Hesp.); g – ribbon-like caudicle (Pleurothallis grisebachiana); h – elastoviscin threads unifying caudicular tetrads (Pleurothallis pubescens).

There is a strong tendency towards a levelled surface (Fig. 44b: lepanthoid) and a highly reduced sculpture. The exinous layer may be reduced to a thin coating (Fig. 44b: Lepanthes) or may disintegrate via the following evolutionary sequence: punctateàfossulateà(reticulate)/gemmate/ octomerioid (Fig. 44c-f). A classic reticulate pattern, rare anywhere in Pleurothallidinae (Stenzel 2000), was observed in this study only in non-Antillean material of Pleurothallis ghiesbreghtiana (Fig. 44d).

[page 74↓]
Fig. 44: Types of surface and sculpture of the exinous layer in Cuban pleurothallids.

a – aciantheroid surface (Pleurothallis wilsonii); b – lepanthoid surface (Lepanthes diaziae); c – punctate fossulate sculpture (Pleurothallis papulifolia); d – punctate reticulate sculpture (Pleurothallis ghiesbreghtiana); e – gemmate sculpture (Pleurothallis sertularioides). f – octomerioid sculpture (Lepanthopsis pygmaea).

Infraspecific variability of pollen characteristics

Eight specimens of Pleurothallis ghiesbreghtiana A. Rich. & Galeotti, spanning the whole area of distribution (Greater Antilles, Central and northern South America), were examined. Plants from the Caribbean generally have pollinia with a psilate to punctate pattern, whereas those of Central America show a tendency towards octomerioid conditions. Finally, the sample from EC showed the most advanced sculpture with a reticulate pattern. Thus, the further north, the more ancestral conditions we find in the pollen morphology of this species.
Within Cuba several species were represented by multiple samples. Pleurothallis grisebachiana Cogn., a relatively common and morphologically variable endemic, showed the greatest variety in pollen morphology. Samples had been chosen to reflect the species’ phytogeography as accurate as possible (Fig. 45). They include samples from both limestone and serpentine bound vegetation. As a result, the set of sculptures found reflects a presumably natural evolutionary line. Fig. 45 illustrates the distribution of the sculpture types: starting with a psilate surface (4,8), via a puncatate and fossulate sculpture (1,9,3,10) with beginning formation of gemmae in larger fossulae and foveolae (1,2,6,7,10 ) to almost gemmate conditions (4). Some of the populations are represented by more than one plant and in this case different sculpture types can be found even within one population. Perhaps the most striking example is Stenzel 489 from the Sierra de Nipe. Pollinia of this collection show either a psilate or gemmate sculpture. Thus, there is no [page 75↓]phytogeographical or ecological correlation with the sculpture pattern. The most distant populations from the centre of distribution in Oriente show neither an exclusively advanced nor a primitive morphology.

Fig. 45: Distribution of the 10 samples of Pleurothallis grisebachiana for palynological studies (dotted – area of distribution; 1-10 – localities of samples).

Pleurothallis mucronata Lindl. ex. Cogn., a serpentine bound endemic in Holguín, was represented by 3 samples (Sierra de Nipe, Sierra del Cristal, Sierra de Moa) spanning all three mountains the species is currently known to occur in (Fig. 46). All specimens show the same pollen morphology.

Fig. 46: Distribution of the 3 samples of Pleurothallis mucronata for palynological studies (dotted – area of distribution; 1-3 – localities of samples).

Pleurothallis ekmanii Schltr., with a distribution similar to that of Pleurothallis mucronata, was sampled also 3 times (Fig. 47: Sierra del Cristal, Yateras). Again, no differences in pollen morphology was found.


[page 76↓]

Fig. 47: Distribution of the 3 samples of Pleurothallis ekmanii for palynological studies (dotted – area of distribution; 1-3 – localities of samples).

Pleurothallis subgenus Antilla Luer is endemic in the Greater Antilles with ~10 species (Luer 2000), 7 of which were included in this study. All species show a rather homogenous pollen morphology: suborbicular to obtusely triangular, reduced caudicles, sculpture punctate to granulate. The surface shows often an aciantheroid organisation of the tetrads (Fig. 44c), which suggests a closer relationship with that subgenus (Acianthera sensu Pridgeon & Chase 2001).

3.5  Taxonomy

The nomenclatural results as applied in this study with complete synonymy are part of the MS presented earlier (p. 26). There are 39 species referable to Pleurothallis (sensu Luer 1986b) in Cuba. Species with 8 pollinia (P. ekmanii Schltr., P. excentrica (Luer) Luer, P.flabelliformis’ nom prov.) are included.

The following list enumerates all epithets that have been referred to Cuban Pleurothallis (left column). If different, the correct name is given on the right. Valid names are printed in bold type. Homotypic synonyms as well as Grisebach’s names published pro syn. (Grisebach 1866) are not included.


[page 77↓]

Tab. 6: Epithets of Pleurothallis referred in literature to the Cuban taxa. Valid names, if necessary, are given at the right side.

Pleurothallis albida Lindl.

Pleurothallis obovata (Lindl.) Lindl.

Pleurothallis appendiculata Cogn.

 

Pleurothallis aristata Hooker

 

Pleurothallis atropurpurea (Lindl.) Lindl.

Zootrophion atropurpureum (Lindl.) Luer

Pleurothallis bissei Luer

 

Pleurothallis blepharoglossa Luer

Pleurothallis grisebachiana Cogn.

Pleurothallis blepharophylla Griseb.

Lepanthes blepharophylla (Griseb.) Hespenh.

Pleurothallis bovilabia C. Schweinf.

Pleurothallis ekmanii Schltr.

Pleurothallis brachyglottis Rchb. f.

Pleurothallis pruinosa Lindl.

Pleurothallis brachypetala Griseb.

Pleurothallis odontotepala Rchb. f.

Pleurothallis brighamii S. Wats.

 

Pleurothallis broadwayi Ames

Trichosalpinx dura (Lindl.) Luer

Pleurothallis caymanensis Adams

 

Pleurothallis confusa Fawc. & Rendle

Pleurothallis wilsonii Lindl.

Pleurothallis corniculata (Sw.) Lindl.

 

Pleurothallis crassipes Lindl.

wrong classification, mostly Pleurothallis domingensis Cogn.

Pleurothallis cubensis Lindl.

Pleurothallis rubroviridis Lindl.

Pleurothallis denticulata Cogn.

 

Pleurothallis domingensis Cogn.

 

Pleurothallis ekmanii Schlechter

 

Pleurothallis excentrica (Luer) Luer

 

Pleurothallis flabelliformis

nom. prov. in this study for Octomeria prostrata H. Stenzel

Pleurothallis foliata Griseb.

Trichosalpinx dura (Lindl.) Luer

Pleurothallis gelida Lindl.

 

Pleurothallis gemina H. Stenzel

 

Pleurothallis ghiesbreghtiana A. Rich. & Galeotti

 

Pleurothallis grisebachiana Cogn.

 

Pleurothallis grobyi Batem. ex. Lindl.

wrong classification, mostly Pleurothallis grisebachiana Cogn.

Pleurothallis helenae Fawc. & Rendle

 

Pleurothallis hymenantha Lindl.

wrong classification; Pleurothallis corniculata (Sw.) Lindl. and Barbosella dussii (Cogn.) Dod (Stenzel & Llamacho 2002)

Pleurothallis lichenicola Griseb.

Pleurothallis wrightii Rchb. f.

Pleurothallis llamachoi Luer

 

Pleurothallis longilabris Lindl.

 

Pleurothallis longissima Lindl.

Pleurothallis ghiesbreghtiana A. Rich. & Galeotti

Pleurothallis maestrensis

nom. nud.

Pleurothallis mucronata Lindl. ex Cogn.

 

Pleurothallis multirostris Rchb. f.

Pleurothallis racemiflora (Sw.) Lindl.

Pleurothallis murex Reichb. f.

 

Pleurothallis nubigena Lindl.

Pleurothallis corniculata (Sw.) Lindl.

Pleurothallis nummularia Reichb. f.

 

Pleurothallis obliquipetala Acuña & C. Schweinf.

 

Pleurothallis oblongifolia Lindl.

Pleurothallis racemiflora (Sw.) Lindl.

Pleurothallis obovata (Lindl.) Lindl.

 

Pleurothallis odontotepala Reichb. f.

 

Pleurothallis oricola H. Stenzel

 

Pleurothallis pachyrhachis A. Rich.

Bulbophyllum pachyrhachis (A. Rich.) Griseb.

Pleurothallis papulifolia Luer

 

Pleurothallis parvula Ames & C. Schweinf.

Pleurothallis denticulata Cogn.

Pleurothallis platyglottis L. O. Williams

Pleurothallis denticulata Cogn.

Pleurothallis prostrata Lindl.

 

Pleurothallis pruinosa Lindl.

 

Pleurothallis quadrifida (Llave & Lex.) Lindl.

possibly conspecific with P. ghiesbreghtiana A. Rich. & Galeotti; quadrifida would be the valid epithet then, due to priority

Pleurothallis racemiflora (Sw.) Lindl.

 

Pleurothallis racemiflora Lindl. ex Lodd.

nom. illeg.

Pleurothallis richteri H. Dietr.

Pleurothallis wrightii Rchb. f.

Pleurothallis rubroviridis Lindl.

 

Pleurothallis ruscifolia (Jacq.) R. Br.

 

Pleurothallis sertularioides (Sw.) Spreng.

 

Pleurothallis shaferi Ames

 

Pleurothallis testaefolia (Sw.) Lindl.

 

Pleurothallis toaensis

nom. nud.

Pleurothallis tribuloides (Sw.) Lindl.

 

Pleurothallis trichophora Lindl.

 

Pleurothallis trichyphis Reichb. f.

 

Pleurotkhallis tricostata Cogn.

Pleurothallis racemiflora (Sw.) Lindl.

Pleurothallis trigonifolia

nom. nud.

Pleurotkhallis tuberculata

nom. nud.

Pleurothallis univaginata Lindl.

Pleurothallis gelida Lindl.

Pleurothallis urbaniana Rchb. f.

Pleurothallis aristata Hooker

Pleurothallis velaticaulis Rchb. f.

wrong classification, mostly Pleurothallis domingensis Cogn.

Pleurothallis verruculosa

nom. nud.

Pleurothallis wilsonii Lindl.

 

Pleurothallis wrightii Reichb. f.

 

Pleurothallis yamanigueyensis

nom. nud.

All recent studies on the orchid flora of Cuba (Acuña Galé 1939, León & Schweinfurth 1946, Hawkes 1951, Dietrich 1984b) enumerate a total of ~40 taxa in Pleurothallis. Ironically, this work comes to almost the same conclusion. Until the start of this study in 1998, 55 heterotypic epithets that were referred to the Cuban Pleurothallis flora had been validly published. 5 of these are currently treated in different genera, 17 are synonymous with those herein accepted, 4 are based on wrong classifications, and 1 could not be evaluated because of the missing type material (Pleurothallis quadrifida (Llave & Lex.) Lindl.). 5 species new for Cuba have been detected in material from herbaria and field [page 78↓]work (Stenzel & Lllamacho 2002). 6 new epithets have been published (Luer 1998c, 1999a; Stenzel 2001, 2002) since 1998, one of which is treated here as a synonym of Pleurothallis grisebachiana.

In the Cuban herbaria, Pleurothallidinae are notoriously misdetermined. Even if not considering synonymous names, 25% of the material in HAC, HAJB and HPPR had to be revised. The overall portion of wrong classifications, including synonyms, was 40%. Closely associated with this phenomenon is the low quality of Cuban standard works as Acuña’s Catálogo (1939) and the Flora de Cuba treatment by León and Schweinfurth (1946). There are not only taxonomic errors passed on from one work to the next, but plenty of phytogeographical misconcepts, too. León lists 21 of 38 taxa as confined to Oriente. Among these there are species that are not found at all in the Greater Antilles (Pleurothallis hymenantha). In turn, taxa of allegedly Greater Antilles distribution are actually local endemics in Moa-Baracoa (P. longilabris).

3.6 Phytogeography

In the following, Cuban species of Pleurothallis were analysed as to their chorological affinities with certain variables, e.g. islands, vegetation types, geographic and climatological parameters.

3.6.1 Phytogeographic relationships of the Greater Antilles with other neotropical areas

There are ~ 70 species of Pleurothallis in the Greater Antilles, 68% of which are endemic to one of the islands and ~80% are confined to the Archipelago. Endemism within island boundaries does not reach that rate. Yet, Pleurothallis shows a higher endemism than orchids in general. Comparing recent rough estimates of Cuban orchidaceous endemism (Dietrich 1984b, 1989b; Trejo-Torres & Ackerman 2001) which rate ~1/3 as endemic, Cuban Pleurothallis shows a much higher geographical restriction on the island level. Fig. 48 shows species totals and the endemic portion of the Greater Antilles islands. Hispaniola and Cuba have rather similar values, with the former being slightly richer in the endemic portion (but see p. 141 for objections) whereas in Jamaica the level drops sharply. Puerto Rico, finally, has no endemic Pleurothallis at all.


[page 79↓]

Fig. 48: Pleurothallis: absolute number of species occurring on the Greater Antilles islands and the endemic portion (absolute and percentage).

Species that are not confined to a single island show the following distribution pattern (Fig. 49). 8 species are endemic in the Greater Antilles. Of the 15 taxa that reach beyond the island arc, 4 are confined to Central America and another 4 to Central America-South America. 6 are Pan-Caribbean elements (West Indies, Central America, South America) with one species occurring in Florida too. Only one taxon is found in the Lesser Antilles and South America. There is no indication for the disjunction Greater Antilles-South America! All islands reflect more or less the Greater Antillean proportions of the respective elements; however, Cuba comes closest to absolute numbers.

Fig. 49: Pleurothallis: distribution of species that are not endemic on the island level.

GA - Greater Antilles, LA - Lesser Antilles, CA - Central America, SA - South America). Bars show the absolute number of species of a given distribution (e.g. 3 Puertorican species are endemic in the Greater Antilles.


[page 80↓]

There is a chorological bipolarity in the Greater Antilles in that most species are either endemic on one island (49 spp.) or are widespread in the West Indies, Central America or/and South America (15 spp.). By way of contrast, there are only a few Greater Antillean endemics (8 spp.) which are confined to more than one island within the archipelago (Fig. 50).

Fig. 50: Greater Antillean Pleurothallis: levels of endemism. Bars show the number of species confined to a certain area.

The set of those 23 species which are not confined to only one island was used to find phytogeographical relationships among the West Indies, adjacent Central America and South America. It turned out that the topologies obtained by MP analyses depended heavily on the areas included and how these areas were defined. MP trees reflect relationships not only based on shared species (coded 1), but on absent species too (0). Since MP algorithms do not weight character states, the absence of a species will group areas just as will do the presence. Hence, areas poor in diversity will a priori be clustered regardless which species they share. To give an example, Grand Cayman shares its only species with West Cuba. Analysing the Greater Antilles islands and adjacent continental areas, Grand Cayman came out as sister to the Lesser Antilles in all MP trees. However, it does not share a single Pleurothallis with that archipelago. The grouping came out only by the general poorness of the local floras. When Cuba was split into 3 subareas (West, Centre, East), 4 MP trees resulted from that matrix with Grand Cayman falling sister to the Lesser Antilles still in 3 trees. Finally, after the exclusion of the outgroup, one most parsimonious tree was found with Grand Cayman forming a clade with West Cuba! Thus, the presence of a 0-coded outgroup can have strong influence on the topology, affecting especially those areas with low diversity. The same effect is apparent in several phytogeographic studies using MP analysis. (Trejo-Torres & Ackerman 2001) examined phytogeographical relationships in the Antilles based on MP analysis of orchid distributions. The trees were Lundberg rooted. A closer look at the distribution within trees [page 81↓]shows that basal branches of the majority tree are generally poor in species numbers. Diversity rises with growing distance from the outgroup, hence, basal units may have been grouped above all by the shared absence of taxa which is not necessarily a reflection of true relationship. If using MP in this context, one should be aware that those clades with the greatest distance from the outgroup or units with low diversity, reflect the information in the matrix best. Although the authors discuss the influence of species numbers (Trejo-Torres & Ackerman 2001: 781), they do not return to the original phytogeographical matrix, to detect the influence of species absence on the topology among island that are poor in taxa. MP related pitfalls and their avoidance have been described in the original papers on PAE already (Rosen & Smith 1988, Rosen 1992). Yet, to date one can find misconcepts of MP analysis (Judd 2001: half of matrix including regional endemics, i.e. parsimony uninformative)

As a consequence, outgroups were excluded from the following analyses. The general floristic affinities between the Greater Antilles and continental areas as inferred from chorological patterns in Pleurothallis are illustrated in Fig. 51. This tree is based on 15 taxa of Caribbean and continental distribution and clearly shows the closer relationships between the Greater Antilles and Central America. South America, and even more the Lesser Antilles, are floristically less tied to the islands. In the case of South America, which does not border the Greater Antilles, this does not automatically mean a disjunction, since all but one species occurring in South America can be found in Central America, too. Likewise, all but one taxa in the Lesser Antilles can be found in South America and/or Central America, too. The descending order reflects actually more the arithmetic similarity of the Greater Antilles with Central America (14 of 15 taxa), South America (11 taxa) and the Lesser Antilles (7 taxa).

Fig. 51: Floristic affinities between the Greater Antilles and adjacent neotropical areas. MP tree based on the distribution of the 15 Greater Antillean species that occur outside the archipelago.

However, the relationships of the Greater Antillean islands with adjacent continental areas and among each other are not equally developed. A complete analysis of the islands, the Lesser Antilles, Central, and South America left some branches unresolved in the strict consensus tree, which is due to the small number of species shared by the areas. As a consequence, in order to compare affinities of the individual Greater Antilles islands with [page 82↓]adjacent areas, the relationships with South, Central America and the Lesser Antilles was analysed independently. In the case of South America and the Lesser Antilles, these areas fell sister to the Greater Antilles (trees not presented) with Puerto Rico as the nearest branch, i.e. both areas had closest affinities to the smallest and easternmost island of the Greater Antilles. Central America, however, formed a group with Cuba-Jamaica, stressing the closer affinities between nearby continental areas and the western Greater Antilles islands (tree not shown). The underlying chorological pattern is represented by two species that are endemic to Cuba-Jamaica and three confined to Cuba-Jamaica-Central America. Hispaniola is tied to that group only by sharing one taxon with Cuba and another with Cuba-Jamaica-Central America. Summing up, the relationships of the islands with each other as well as with adjacent neotropical areas are not strongly developed, i.e. in most of the cases they are represented only by weak chorological imbalances.

Fig. 52: Floristic affinities between Cuba’s three mountainous areas, the Greater Antilles and adjacent continental areas. Only most parsimonious tree found.

The irregular distribution continues as one zooms further into the Antilles. Within Cuba, Pleurothallis is found in all three major mountainous areas, as reflected by the principal collecting areas (Fig. 2). However, species diversity is highly skewed among the three areas (Fig. 53). Fig. 52 shows the relationships among Cuba’s subregions and with respect to other islands and neighbouring areas. Cuba’s central part shows more affinities with the East, due to three Cuban endemics shared. The eastern part of Cuba in turn is closer allied with Jamaica (two species endemic in these areas). Again, Cuba and Jamaica fell sister to Central America. This region shares a number of taxa, which are not [page 83↓]found in Hispaniola, Puerto Rico, South America and the Lesser Antilles. As mentioned before, the number of those taxa which would distinguish areas is too small and their distribution often contradicting. Thus minor relationships between Hispaniola and East Cuba (one species), as well as Hispaniola, Puerto Rico and East Cuba blur the topologies.

3.6.2 Distribution patterns on the island of Cuba

Generally, pleurothallid species are confined to the mountainous western, central and eastern end of the island. Extrazonal locations comprise the coastal lowlands of Guanahacabibes (Pleurothallis caymanensis, Pleurothallis oricola) and Canasí (Pleurothallis corniculata).

East vs. Central vs. West Cuba

As mentioned above, species of Pleurothallis are not evenly distributed among the three main areas. On the contrary, there is an overwhelming floristic richness in Oriente (36 taxa), whereas the central (11) and western (9) areas are poor both in species diversity and endemism (Fig. 53).

Fig. 53: Pleurothallis: number of species in East, Central and West Cuba. Island totals are given again for comparison.

Floristic affinities of the three subregions with neighbouring areas have been presented earlier (Fig. 52). East Cuba shows closest relationships with Jamaica (Pleurothallis odontotepala, P. nummularia) and Hispaniola (P. denticulata). Moreover, eastern Cuba shares three endemics with Central Cuba, P. grisebachiana, P. murex and P. trichophora, as well as two taxa of wider distribution, P. pruinosa and P. wilsonii, none of which is [page 84↓]found in West Cuba. The latter, in turn, accommodates one species not found in the other subregions that tie it with Central America and the other Greater Antilles (P. ghiesbreghtiana) and one with the distribution West Cuba – Grand Cayman (P. caymanensis).

Distribution ~ ecology: elevation

Pleurothallid orchids were found to inhabitate the whole vertical range from sea level to the summit of Pico Turquino (Fig. 54). The maximum species diversity is found between 300 and 900 m with the peak at 600-700 m elevation. Remarkable are the relatively poor higher elevations. Ranges above 1300 m refer exclusively to the Turquino massif (a), which is especially poor in species diversity in the 300 m cloudforest belt [!] above 1400m. The small peak below 1200 m (b) is brought about by the enriched summit floras of several mountain tops reaching just this height (Pico Cristal, Gran Piedra, Loma El Gigante). The massive concentration of taxa around 600 m (c) is due to the accumulation of endemics from the Nipe-Cristal-Moa-Toa and Sierra de Imías range along with the flora of the mogote summits. Finally, two species from Guanahacabibes and one from Moa (d), show a coastal distribution which is very unusual for the typically mountain bound genus Pleurothallis.

Fig. 54: Pleurothallis: vertical distribution of species at different elevations. Numbers show the total of species that have been collected in the respective vertical section of 100 m. Arrows (a-d) are explained in the text.

Concerning the altitudinal amplitude, most species occur in an elevation belt of 300-1000 m in height (Fig. 55). Of course, these belts may differ regarding the absolute height they are inserted in. Thus, P. prostrata and P. denticulata occur both within a belt of about 400 m, the former between 600-1000 m, the latter from 1100-1500 m.


[page 85↓]

Fig. 55: Altitudinal amplitude of Cuban Pleurothallis. Values indicate the number of species that share the respective altitudinal range, e.g. 3 species occur within an altitudinal belt of 1000 m in height. A polymorph trend curve (5th order) is added.

The greatest altitudinal amplitude can be observed in Pleurothallis domingensis (Δ1800 m) and P. racemiflora (Δ1700m), two Greater Antillean endemics, but with very close relatives in Central (Luer 1998b) and South America (Luer 1998a). Other species of likewise ample altitudinal distribution comprise rather widespread taxa like Pleurothallis corniculata, P. gelida, P. obovata, P. ruscifolia, P. sertularioides, P. tribuloides. On the other hand, Cuban endemics tend to be restricted to a narrower altitudinal belt (Fig. 56).

Fig. 56: Pleurothallis: Correlation between general distribution of Cuban species and their altitudinal amplitude. Note that the altitudinal classification does not represent the range but the width of the elevation belt the species occur in! Horizontal distribution (area) is growing on the x-axis from left to right, ecological amplitude from the foreground towards the background. Given are the totals of species. See p. 17 for further methodical details.

[page 86↓]Distribution ~ ecology: climate

Although Borhidi’s (1996) climate map of Cuba, based on data from 217 stations, is the best available, it often provides too low spatial resolution yet, to assess climatic affinities in detail. In the following, a list is presented of those climate types where pleurothallid orchids occur. It has to be stressed, however, that habitat preferences depend often on microclimatic features that are not reflected in Borhidi’s system. These empirical data, gathered during extensive field work, are given where necessary.

Only 3-6 of the 15 types listed for Cuba by Borhidi (1996) seem to be too hostile for pleurothallids. These comprise types with extended arid periods and/or a combination of high temperatures and low amounts of precipitation. The remaining types are suitable for Pleurothallidinae to various degrees. Although the evaluation is empirical, those types that appear to host the greatest number of pleurothallids are marked in bold type.

  1. Summer dry tropical climate: 3 (b-)c-d T. 1000(?)-1500 mm/a. (5-)4-1 dry months. This special type prevails only at the NE coast of Oriente and is brought about by the contact of bixeric climates in the lowlands with neighbouring wet climates in the mountains. The type can be included only tentatively, since it is hard to distinguish from the bixeric type on Borhidi’s map (Borhidi 1996). If at all, habitats are restricted to gallery forests which provide a suitable microclimate especially in localities with an extended arid season (see p. 90 #3).
  2. Winter dry tropical climate: 4 (b-)c -d Th . 1300-2400 mm/a. (5-)4-1 dry months. This is the most common type in Cuba (Borhidi 1996). Areas that accomodate Pleurothallis comprise lowlands (Guanahacabibes), colline (Pinar del Río, Escambray, Sierra Maestra: -800 m) to submontane belts (as colline, but 800-1440 m). Localities with a strong to moderate dry period (Guanahacabibes: 5 months) show secondary microclimatic traits with a higher level of air humidity (see p. 90 #2) that moderates the impact of drought. The same applies to habitats at lower and middle elevations close to waterways (see p. 90 #3). A third microclimatic trait related to relief is found at lower altitudes in the Sierra de los Órganos (see p. 90 #1). Mesoclimatic features as condensation belts provide an additional source of shade, humidity, and precipitation at higher elevations (see p. 90 #4).
  3. Bixeric tropical climate: 5 d Th. 1400-1800 mm/a. 1-2 dry months. This type occurs only in NE Oriente in Moa, Toa, and Baracoa at lower elevations. Special microclimatic features provide favourable conditions for microphytic orchids (see p. 90 #3). Several collections of pleurothallids orchids (P. obovata, P. sertularioides) around Siboney (S of Gran Piedra) would fall in the category 5 b or 5 a even. Unfortunately, no further information, concerning the specific climatic features of [page 87↓]this peculiar locality could be obtained. Considering the strong influence of meso- and microclimatic traits that have been observed to blur macroclimatic patterns in Cuba, it is safe to assume that this area must have a strong secondary climatic impact either from the nearby shore or from altitude.
  4. Axeric tropical climate: 6 a-b . 1400-3200(-5000) mm/a. No dry period. Restricted to E Sierra de los Órganos, Sierra del Rosario (Taco Taco, Rangel?) and above all the Moa-Toa-Baracoa range at middle elevations (6 a), as well as in (sub‑)mountainous belts (600-1400m) in Central and East Cuba (6 b). Again, macro- and mesoclimatically drier habitats show sources of additional humidity and precipitation (see p. 90 #3-4).
  5. Tropical montane climate: 7 a -b. >2000 mm/a. No dry period. Restricted to the central Sierra Maestra (7 a) and the Pico Turquino massif (7 b). The latter type seems to host much less Pleurothallis species. The high ridges above 1800 m fall under its influence. Local meso- and microclimatical phenomena smooth the harsh impact of insolation and drought in exposed epiphytic and epilithic habitats (see p. 90 #4).

Distribution ~ ecology: vegetation types

It is essential to bear in mind the definition of the vegetation types as employed here (p. 15). Despite the adoption of many formations sensu Borhidi (1996) there are differences which should be considered. Distribution data of the individual species in natural and secondary vegetation types are listed in the second part of this thesis. Fig. 57 shows the totals of species that have been found in the different vegetation types.

Concerning the importance of natural habitats, it is interesting that 12 of the 39 species could be found in areas disturbed by man or even in cultivations. The latter, however, has to be considered with caution, since the relevant data is drawn from rather indifferent collecting information, e.g. “en montes y cafetales“. The data for secondary shrubwoods is almost completely obtained from a destroyed montane rainforest in the Sierra de Imías (Los Calderos), a low vegetation termed tree-fern-Dicranopteris-shrubwood (matorral seminatural con helechos arborescentes y Dicranopteris spp. according to Borhidi, 1996). This is the only case where an endemic Pleurothallis (P. rubroviridis) has been found in secondary formations. All other species that were collected in vegetation types affected by man represent widespread taxa of Antillean or Pan-Caribbean distribution.


[page 88↓]

Of the natural formations defined by Borhidi (1996) which were partially adopted here, Pleurothallis is

  1. present in all non-coniferous forest types except semideciduous xerophytic forests. Seasonal rainforests, were excluded from the screening since “undisturbed stands are hard to find anywhere in Cuba” (Borhidi 1996).
  2. absent in most shrubwood communities. The major exception from that rule are charrascal formations, which accommodate a great number of species.
  3. strongly under-represented in all types of pine forests.
  4. entirely absent in savannahs and grasslands, mangroves, coastal vegetation on both sandy and rock ground.

Species diversity – With the exception of species poor cuabales, dry, and semi-deciduous forests, species of Pleurothallis are generally not found in lowland formations. All other types are bound more or less to the colline, submontane and montane belt. Unexpectedly, elfin formations, the hallmark of which is epiphytism, are relatively poor in pleurothallids. In fact, on the summits of the Turquino massif there are relatively extended areas, that seem to be almost free of them. This is especially striking when ascending the traditional trail to the Turquino peak. Below La Aguada de Joaquín along the crest a very rich epiphytic layer with no less than 10 species of Pleurothallis can be observed. The second steep part between La Aguada and Pico Joaquín hosts almost no plants of this genus. There are still specimens of Lepanthes growing on the trunks, but the impression of a highly reduced phanerogamous epiphytic layer is striking. The summit crests again are characterised by numerous epiphytes that grow in and on the dwarf forests and shrubwoods. The discontinuity of the distribution even within small distances seems to be the result of unfavourable light conditions: the steep part between La Aguada and the summit crests is exposed to the West, i.e. least insolated. Furthermore it is dominated by dense forests with rather closed canopy. The crests below La Aguada and on the summit ridges receive more light due to their exposition and a broken and partially open vegetation. It is here that the greatest number of orchids can be found in epilithic, pseudo-terrestric and epiphytic habitats.
Among the simple formations, not surprisingly, montane and submontane rainforests are the ones with the richest pleurothallid floras.
Among vegetation complexes, gallery forests show the greatest diversity. Gallery forests, as defined by Capote & Berazaín (1984) include smaller rivers and creeks, the banks of which are generally rich in epiphytes. These stands were difficult to score, since it is almost impossible to draw the line between the bank vegetation and the adjacent forests or shrubwoods. Therefore, high species numbers in (sub)montane rainforests and evergreen forests are partially brought about by scoring the species double, both under [page 89↓]“gallery forest” and an adjacent vegetation type. Further from the waterway, the adjoining forests or shrubwoods were, in fact, often free of the respective species. One of the most illustrative examples can be found in Sierra del Cristal following the lower (NàS) and upper (SWàNE) course of Río Levisa.
Pine forests have been found to be very poor in orchid diversity. During the field work for this study only drought-resistant bromeliads and mesophytic orchids with developed storage organs (e.g. Epidendrum s.l., Oncidium) were found in these formations. However, closeby waterways may change the picture. Thus, some pleurothallid orchid have been found and reported for this vegetation type too. In the Sierra del Cristal the large pine-charrascal of the SW slope below the summit is virtually free of pleurothallids. Only P. ekmanii has been found, growing pseudo-terrestric or epilithic among and on rocks. The N section of Río Levisa occasionally touches stands of pine forests. Pleurothallid species growing on conifers have been found only here. Under normal conditions, i. e. away from additional water sources like rivers, pine forests seem to be generally free of Pleurothallis species.
Semi-dry serpentine shrubwoods (charrascal) receive their high score partially due to the spatial closeness to the riverside vegetation. However, on high mountain plateaus (e.g. Toldo), there do exist extended charrascal areas with many species of Pleurothallis.
Karstic forests (mogotes) are the other complex that receives relatively high scores. It is potentially composed of at least 3 forest types, montane rainforest (summit of Pico Potrerillo), seasonal evergreen rainforest (most mogotes of Oriente), semideciduous forests (predominating on and around western mogotes). Karstic forests are included as a separate unit for traditional and conservation reasons.

Endemic portion – Concerning the endemic portion (island endemics) of the species present in each type (Fig. 57, in red), four formations show values of at least 50%: (sub)montane rainforest on serpentine, charrascal formations, pine forest on serpentine and gallery forests. The first three appear exclusively on serpentine rock. Gallery forests, too, receive high scores from the serpentine-bound endemics (9 of 13). The close affinities among these formations (pine forests excluded) is illustrated in Fig. 58. In montane rainforests and karstic forests, still 25-35% are represented by island endemics.

Most of the endemic taxa occur in more than one vegetation type, i.e. formations are poorly defined by pleurothallid orchids! Only three species are currently known to be restricted to just one type: Pleurothallis murex, P. oricola, P. trichyphis. However, even in the case of these three taxa conclusions have to be drawn with care. Experience from the distribution patterns of other taxa has shown that presumably local endemism often turned out to be a collection artefact.


[page 90↓]

Fig. 57: Pleurothallis: Occurrence of Cuban species in different vegetation types. Given are the totals of the species found in the respective formation along with the portion of Cuban endemics (in red; not shown in secondary formations).

As mentioned before, in many cases only special microclimatic situations allow the colonisation by microphytic orchids. For these in general and the non-pseudobulbous3 pleurothallids in particular, even moderate climates would probably prevent a successful establishment. During field work empirical data on climatic conditions was collected to characterise habitats. Drawn from these observations, the following list will summarise special meso- and microclimatically defined habitats that may explain the occurrence of Pleurothallis under otherwise unfavourable macroclimatic conditions

  1. – The haystack mountains (mogotes) in West Cuba show a mosaic of microclimatic niches, that are mainly influenced by the relief. The so called hoyos, sagged plateaus, that develop a seasonal evergreen forest on the ground, are characterised by a higher humidity and are less insolated. Pleurothallis [page 91↓] caymanensis, P. corniculata, P. tribuloides and P. sertularioides can be found just on the border to adjacent stands of drier and more open stands of mogote forests. A special microclimatic phenomenon occurs where the hoyos are open to one side. These areas are especially suited for epiphytes, since they benefit from the humid air of the inner hoyo, that flows out during the morning hours (R. Novo Carbó, Pinar del Río, pers. commun.).
  2. Partially inundated areas (swamp vegetation). – On Guanahacabibes peninsula, there are two types of forests, dry forest (microphyllous evergreen forest) and semi-deciduous forest. In some areas underground channels lead seawater through the karstic rock. Open ponds along with the nearby shore produce a high humidity that attracts several species of orchids and bromeliads (Poza Redonda, María La Gorda, Barra de La Sorda). Among these are Pleurothallis caymanensis and P. oricola.
  3. Small creeks and rivers. – As mentioned before, gallery vegetation accommodates the majority of the Cuban species of Pleurothallis and even Pleurothallidinae. In these formations, species are able to colonise low elevations and unfavourable habitats as rocks, pine forests, cuabales, charrascales and semi-deciduous forests. To give an example: the S slope of the Cajálbana mountains is generally free of microphytic epiphytes. Yet, along creeks, a few meters away from sun-torched cuabal vegetation, species of Lepanthes can be found.
  4. Crests. – While the previous type plays a major role at lower elevations, crests are more important above the condensation belt (900 m, sometimes lower). These habitats accommodate the small species of the Pan de Guajaibón, Sierra de Escambray, Sierra de Nipe, Sierra de Cristal, Sierra Maestra, Yateras and Sierra de Imías. The cloud-enveloped summits and crests of the Sierra Maestra chain often show the same set of species (Pleurothallis denticulata, P. helenae, P. obliquipetala, P. odontotepala, P. racemiflora, P. trichophora and Lepanthopsis microlepanthes).
  5. Ground proximity – Pleurothallis usually occur on trunks or rocks close to the ground, i.e. in < 3 m height. Specimens have been found only exceptionally as high as 5 m above the ground. In these cases, plants grew either on foggy ridges or specimens belonged to the hardier taxa (P. obovata, P. gelida) with a high ecological amplitude. This spatial proximity to the ground may be connected to the substrate bound pollinator set, at any rate it benefits from the increased humidity of the terrestric strata.

Observations in the field had suggested, that some of the vegetation types are more similar to each other concerning the set of pleurothallids that they accommodate. These [page 92↓]floristic relationships of the different natural vegetation types are illustrated by a MP analysis based on the distribution of Pleurothallis species.
When analysing all formations, 23 [!] trees were computed. Bearing in mind the limited applicability of the MP algorithm discussed earlier (p. 78), all formations with less than 6 taxa present were excluded from the matrix in the next run. The resulting tree (strict consensus of two trees computed) is shown in Fig. 58. There seems to be a striking dissimilarity within groups, e.g. the combination of shrubwoods and rainforests. The underlying pattern is apparently based on geology, which forms two major groups: 1) formations on serpentine and 2) formations on volcanic rock and limestone. The grouping of elfin and montane rainforests does not surprise, since these two types are often found as a neighbouring vertical succession (Sierra Maestra) and both share a number of taxa not present in other types (Pleurothallis denticulata, P. obliquipetala, P. odontotepala, P. trichophora). Another 4 species (Pleurothallis rubroviridis Lindl., P. domingensis, P. ruscifolia, P. wilsonii) tie this group with karstic and dry forests. The latter has, despite the topology found, more affinities with Karstic forests (P. caymanensis, P. wilsonii) than with seasonal forests or pine forests on serpentine. The alliance is probably an artefact caused by the low number of species present (see p.78).

Fig. 58: Floristic relationships between major vegetation types inhabited by Pleurothallis (>5 species present). Strict consensus tree of two most parsimonious trees found.

At first sight, the other group is not as clearly defined as the first one. The three formations pine forests, rainforests and charrascales are associated with ultrabasic rock. Surprisingly, gallery forests fell just in this group, a topology that is 100% supported by bootstrap tests. Gallery forests seem to play a major role in areas with serpentine.


[page 93↓]

As with other variables, species are not evenly distributed among the natural Cuban vegetation types. The most widespread taxa are Pleurothallis corniculata, P. gelida, P. obovata, P. sertularioides, and Pleurothallis tribuloides occurring in at least 8 of the 13 natural types. They are all of major general distribution. On the other hand, empirical data show that endemics might be restricted to only a small number of formations. Fig. 59 shows that there is indeed a correlation between the two variables, in that the most widespread taxa occur in the greatest number of formations and vice versa. The only exception from that rule is the endemic P. grisebachiana which occurs in 6 natural types, an unusually high number among endemic taxa.

Fig. 59: Pleurothallis: Correlation between general distribution of Cuban species and their occurrence in different vegetation types. Horizontal distribution (area) is growing on the x-axis from left to right, ecological amplitude from the foreground towards the background. Given are the totals of species.

Distribution ~ ecology: geology

Fig. 60 shows the geological affinities of Cuban endemics. The association with a single type of rock is striking. The rate of petrologic endemism would still be higher if Greater Antillean endemics of restricted distribution (two islands) would have been included. P. caymanensis (West Cuba – Grand Cayman) is known only from karstic forests. P. odontotepala (East Cuba – Jamaica) has been found so far only on volcanic rock. The correlation between overall distribution and the level of petrologic restriction, is shown in Fig. 61.


[page 94↓]

Fig. 60: Pleurothallis: distribution of Cuban endemics among different petrologic types. Given are the absolute numbers of species. P. murex was excluded because of unreliable data.

Fig. 61: Pleurothallis: Correlation between general distribution and the occurrence on a different number of petrologic types (ecological amplitude). Horizontal distribution (area) is growing on the x-axis from left to right, ecological amplitude from the foreground towards the background. Given are the totals of species.

According to Cuban data, widespread species occur mainly on all types of rock distinguished here. Endemics, on the contrary, are restricted mainly to one type of rock, which reflects the strict geological bonding of most of the Cuban endemics shown in Fig. 60.

Distribution ~ ecological amplitude

Preliminary studies and field observations had indicated a correlation between the general distribution of Pleurothallis species and their ecological amplitude.

The following diagrams (Fig. 62) show the relationships between the horizontal distribution (area) and other ecological variables, i.e. altitudinal amplitude, number of vegetation types and number of petrologic types. It should be emphasised that these variables are always [page 95↓]of quantitative nature, i.e. the aim is to find if there is a correlation between the overall area of distribution and the level [!] of ecological restriction. To give an example, species are not classified regarding their distribution in different vegetation types (quality) but the number of formations they occur in (quantity), e.g. the species that occur in all 7 localities (Pan-Caribbean elements) grow in 6 vegetation types on average (Fig. 62 – b).
Concerning the analysis of vegetation types, phytosociological classifications are largely based on priorities employed by the author (see p.15). In order to compare data, both the classification adapted from Borhidi (1996) which was used in this work (Fig. 62- c) and the system proposed by Capote & Berazaín (1984) (Fig. 62 - b) were analysed, too.

Fig. 62: Pleurothallis: Correlation between horizontal distribution and different ecological variables. Species are classified by the overall area of distribution expressed by the number of localities they are found in. Localities 1-6 are Greater Antillean areas, #7 represents the adjacent areas, Lesser Antilles, Central and South America (see p. 17). Analyses are based on mean values (standard deviation given in the graph) except for species occurring in 3,4 and 6 localities, which are single entries.

Spearman correlation, N= 35; a – rs= 0.473, P= 0.004; b – rs= 0.506, P= 0.002; c – rs= 0.531, P= 0.001; d – rs= 0.728, P< 0.001).

There is a significant correlation between the overall area of distribution and the ecological amplitude of the Cuban species in all tests, i.e. the most wide-spread taxa are the most euryoecious ones.


[page 96↓]

3.7  GENETICS

DNA extraction

DNA isolation results from material collected in 1998 which had not been stored in a deep freeze immediately showed a quick deterioration process depending on the time they had been exposed to (subtropical) room temperature (Fig. 63).

Fig. 63: Agars gel pictures of DNA extractions from material collected in 1998 (a) and 1999/2000 (b). The arrow marks sample Stenzel 634, which apparently did not contain exploitable DNA material.

On the contrary, material gathered in 1999 and 2000, which had been maintained right after desiccation at least at a temperature of ~4°C, gave excellent results (Fig. 63b). Negative agars gel analysis not always meant complete failure of the extraction. In some cases (Fig. 63a: arrow), PCR did work, though gel analysis had indicated absence of any DNA in the extract. Extractions from herbarium material, obtained from traditional herbarium collections failed in P. appendiculata.

Alignments

Unaligned ITS sequences differ only slightly in length. The shortest sequence was found in Pleurothallis pruinosa (542 bp) due to a gap of 84 bp in the 5.8S gene. Pleurothallisflabelliformis’ has a major deletion close to the pruinosa gap too (32 bp, total length of sequence: 609 bp). The rest of the species yielded sequences between 622 bp (Pleurothallis domingensis) and 640 bp (Pleurothallis rubroviridis).


[page 97↓]

The following table summarises the length variability of the sequences.

Tab. 7: Length variability (bp) of the unaligned sequences of Cuban Pleurothallis species. Two major deletions in 5.8S (Pleurothallis pruinosa and P.flabelliformis’) were ignored in the table.

ITS1

5.8S

ITS2

ITSges

min.

max.

 

min.

max.

min.

max.

213

227

164

244

254

622

640

CLUSTAL was run with different options. Different delay values (5%, 30%, 50%), i.e. the amount of bp differences by which a sequence’s addition is postponed, did not alter the output alignment. Gap open penalties of 10 and 15 produced identical alignments. Lower values extended insertions as follows: 5: +3 bases, 4: 17 bases, 3: 29 bases.

The five matrices (Tab. 8) used in this study differ mainly in the way how gaps were treated. Of the two initial CLUSTAL alignments received with gap costs 4 (hereafter ITS4C) and 15 (ITS15C) another two were derived by deleting ambiguous gaps (ITS4CR and ITS15CR resp.). A fifth set originating from ITS4C was achieved by eliminating all gaps (ITS4D). All alignments were manually adjusted and gaps presumably caused by single events (duplications) were coded as one base. Thus, the treatment of gaps as a fifth base seemed to be reasonable.

Tab. 8: Characteristics of the five alignments used in this study: gap tolerance, length and informative sites.

matrix

initial gap cost (CLUSTAL)

manual adjust.

indel coding

deletion of ambiguous indels

complete deletion of indels *

Σ loci with gaps *

Σ bases:
total, variable,
parsimony- informative

ITS4C

4

yes

yes

no

no

150

704, 552, 318 (45%)

ITS4CR

4

yes

yes

yes

no

118

672, 520, 291 (43%)

ITS15C

15

yes

yes

no

no

116

686, 537, 316 (46%)

ITS15CR

15

yes

yes

yes

no

80

647, 499, 282 (43%)

ITS4D

4

yes

yes

yes

yes

0

553, 193 (35%)

* – two major gap segments in Pleurothallis ‘flabelliformis’ and P. ruscifolia were neither deleted nor counted.


[page 98↓]

The next table shows the alignment ITS15C.

Tab. 9: Matrix ITS15C. Names of the sequences follow species’ epithets. Given are the two sequences of Pleurothallis pruinosa as well as those of the different accessions of P. ghiesbreghtiana and P. trichophora. Dilomilis montana represents the sequence used by Pridgeon & al. (2001) as one outgroup (AF262915).

ITS variability among accessions turned out to be very different. Within species boundaries, ITS differed up to 7% (Pleurothallis brighamii), being much higher than in pairs of closely related species (Pleurothallis domingensis ~ Pleurothallis velaticaulis: 3,5%). Perhaps the most striking case of stability is the species pair Pleurothallis gemina [page 105↓]and Pleurothallis wrightii which shares the same sequence!

Tab. 10: Sequence divergence (total of mismatches and indel bases) at species level and among species.

 

ITS1

5.8S

ITS2

Pleurothallis brighamii *

17

11

17

Pleurothallis ghiesbreghtiana

1

?

?

Pleurothallis ruscifolia

12

2

4

Pleurothallis sertularioides

7

0

2

Pleurothallis tribuloides

6

0

3

Pleurothallis trichophora

8

1

7

Pleurothallis domingensis ~ Pleurothallis velaticaulis

8

1

15

Pleurothallis gemina ~ Pleurothallis wrightii

0

0

0

* – incomplete ITS2 sequence (AF262925).

Mutation rate was found to be unequally distributed among loci. Fig. 64 shows the entropy along the whole alignment (ITS4C). 5.8 S gene (pos. 270-433) is marked by an abrupt drop in mutations. However, there are islands of increased polymorphism especially in those 20% of the gene which neighbours ITS2.

Fig. 64: Entropy (variability) along all loci of one sequence alignment (ITS4C). Given is the amount of variability in each column (base position). Species with larger deletions (>6 base pairs, Pleurothallisflabelliformis’, P. pruinosa p.p.) and those with only incomplete sequences (ITS2 missing: P. ghiesbreghtiana) were excluded prior to analysis.

Phylogenetic analyses

To test the substitution saturation of the sequences, transition and transversion portions were plotted against genetic distance (Fig. 65, Fig. 66). (AóG, CóT) are known to occur at higher rate than transversions (AóC, AóT, AóT, GóT). This is seen [page 106↓]in the diagrams presented here. Transversion are accumulating at a more or less linear rate, whereas transitions show an exponential growth and saturate much quicker. The saturation (a horizontal graph) however is not yet reached in the sequences employed.

Fig. 65: Transition (s) and transversion (v) proportion versus distance (Tamura & Nei 1993) of the ITS4C matrix.

Fig. 66: Transition (s) and transversion (v) proportion versus distance (Tamura & Nei 1993) of the ITS4CR matrix.

Comparing the diagrams from the different matrices it turned out that the theoretical initial growth (exponential in transitions, linear in transversions) is blurred in sequences [page 107↓]containing indels. Since length mutations are rare events they are more apparent in distant taxa, i.e. their influence on the transitions/transversion ratio is much stronger towards the right part in the diagrams. In the initially homogenous segments s/v ratios should then be as divergent as in sequences of little distance (s>>t).

Thus, the exclusion of gap areas (Fig. 66) lowers the right portion of the s-graph and lifts that of the v-graph.

Cuban Analysis

The term Cuban Analyses, hereafter, refers to those based on the Cuban taxa.

The following table shows statistical results of MP analyses. Gap tolerance thoroughly affected topologies. Best results, i.e. highest resolution of taxa, were achieved with a gap cost of 15 in the initial CLUSTAL alignment and very limited subsequent adjusting by eye.

Tab. 11: Statistical results of MP analyses.

Matrix

(see Tab. 8)

Σ trees

Σ steps

RI

Consensus tree:
Σ unresolved nodes (and branches)

ITS4C

8

1378

-

2 (10)

ITS4CR

3

1258

-

2 (6)

ITS15C

2

1369

0,70

1 (3)

ITS15CR

1

1234

0,68

0

ITSD

8

881

-

2 (11)

Deleting ambiguous indels increased the resolution of the tree (ITSxCàITSxCR). However, a total omission of indels seems to be a loss of indispensable information (ITSD4), which resulted in the collapse of many branches. Generally, the topology of deeper splits, i.e. among distant taxa, is more affected by indel manipulation than relationships among lower ranks. Thus, the deletion of gaps (ITSxCR and ITSD alignments) affected only the relative position of subgeneric taxa (sensu Luer) to each other. Species complexes of lower ranks are rarely affected by any of the manipulations, i.e. relationships within subgenera were nearly the same in all topologies. Thus, the definition of homologies, which depends on gap costs and personal preferences of the author when adjusting the alignments by eye, influences major relationships in the first place!
Though ITS15C had two most parsimonious trees, its clades received stronger bootstrap support than those of the single tree drawn from the ITS15CR alignment. This may be in part due to the reduced number of parsimony informative sites in the latter. Moreover the two trees of ITS15C differed only slightly in having the relative position of Pleurothallis [page 108↓] ghiesbreghtiana and P. pruinosa (short sequence) exchanged. In a second run, with the sequences of P. ghiesbreghtiana being removed, as expected, only one most parsimonious tree was left. Naturally, bootstrap percentages rose substantially. One of the two trees of ITS15C shall be presented here (Fig. 67+Fig. 68).

In the following, clades A-G from Fig. 67 and Fig. 68 are described with reference to the system published by Luer (1986b), if not indicated otherwise.

Fig. 67: One of the two most parsimonious trees from the ITS15C alignment.

Numbers above the branches are bootstrap percentages >50%. Numbers below the branches represent bootstrap support when Pleurothallis ghiesbreghtiana had been removed from the alignment. Cuban endemics are in bold type. The second tree differed only in having the short sequence of P. pruinosa, pruinosa_s, as the basal branch of clade E.

Clade A – This clade comprises three species with 8 pollinia which were published under the generic names Octomeria and Pleurothallis. All are Cuban endemics. The group came out as sister to the rest of the species in all most parsimonious trees from the 5 [page 109↓]alignments. It received 98-100% bootstrap support in all bootstrap analyses, which is partially due to a considerably high branch length (100 steps).

Clade B – Three subgenera are assembled in this group: Antilla Luer, Acianthera (Scheid.) Luer and Apodae-Prorepentia Luer. The former is restricted to the islands of the Greater Antilles where it has 11 species (Luer 2000). Of the four Cuban taxa, two could be sequenced, P. prostrata and P. trichophora. The two accessions of the latter, one from Central Cuba (Stenzel 606), the other from Oriente (Stenzel 630), mark the limits of the geographic distribution of that taxon. The two samples show a relatively high branch length leading to their node and even within there is a fairly great number of steps (4 and 12 resp.)
Subgenus Acianthera was split by Luer into several sections, many of which are represented in Cuba: sect. Brachystachyae Lindl. (Pleurothallis odontotepala, P. papulifolia, P. wilsonii), sect. Sicariae Lindl. (P. rubroviridis), sect. Tomentosae Luer (P. bissei). Morphologically these species have a strong tendency towards succulence, including the flowers. The third subgenus, Apodae-Prorepentia, is represented by just one species, P. testaefolia.
All subclades receive strong bootstrap support, except for P. bissei which in the MP consensus trees ends up either in an unresolved position within clade B (ITS4C), as sister to papulifolia-prostrata-trichophora (ITS4CR, ITS15C: Fig. 67), or in a paraphyletic position to clade B as sister to clades C-G (ITS15CR).

Clade C comprises P. obovata and P. sertularioides, which belong to different subgenera in Luer’s system, Acuminatia (Lindl.) Luer and Specklinia sect Muscosae Lindl. resp. This group is found in all boostrap trees (100%).

Clade D represents Pleurothallis nummularia, which belongs to Luer’s sect. Phloeophilae (Hoehne & Schltr.) Luer of subgen. Acianthera. Here it never fell within this group. The species‘ position is uncertain. In most of the consensus trees it is found as sister to clade C (ITS4CR, ITS15CR) or clades E-G (ITS15C). However, the branch which includes P. nummularia, always collapses in the majority boostrap trees (<50%).

Clade E comprises only two taxa, Pleurothallis domingensis and P. racemiflora. The former belongs to subgen. Crocodeilanthe, the latter has been accommodated as subgen. Dracontia Luer. The group received 95-100% bootstrap support in all consensus trees.

Clade F consists of two taxa attributed to subgen. Pleurothallis sect. Pleurothallis, P. ruscifolia and P. pruinosa, and one classified under subgen. Acuminatia Luer (1999b), P. ghiesbreghtiana. Of the latter only ITS1 and 5.8S p.p. could be sequenced. All alignments (except ITSD) yielded a similar topology with P. pruinosa and P. ruscifolia as sister to P. ghiesbreghtiana, however, with low bootstrap support. The elimination of P. [page 110↓] ghiesbreghtiana from the matrices resulted in bootstrap values bouncing up (Fig. 67 – numbers below branches). A second MP run with only the partial sequence covered by P. ghiesbreghtiana (ITS1 and 5.8S p.p.) showed the same topology as Fig. 67. Bootstrap values from this stripped matrix, naturally, were much lower due to the limited data.

Fig. 68: One of the two most parsimonious trees from the ITS15C alignment (same tree as in Fig. 67).

Numbers above branches are branch lengths. Cuban endemics are in bold type.

The last clade, G, was found in all trees from the 5 matrices. It received high bootstrap support in the case of full (≥ 90%) but less in the case of stripped matrices (70-85%). The clade is subdivided into two groups which have been found again in all consensus trees, both with strong support (≥ 95%). The first one comprises taxa from subgen. Specklinia sect. Muscariae Luer with P. aristata as the type species. The other group consists of taxa treated as subgen Specklinia sect. tribuloides Luer (P. tribuloides) and sect. [page 111↓] Hymenodanthae Barb. Rodr., the latter being divided into subsect. Apodae-Caespitosae (Lindl.) Luer (P. corniculata, P. brighamii, P. trichyphis) and subsect. Longicaulae (Barb. Rodr.) Luer (P. gemina, P. grisebachiana, P. shaferi, P. wrightii). Except for P. brighamii the relationships of all species received moderate to strong support by bootstrap tests.

Complete Analysis

The term Complete Analysis, hereafter, refers to analyses comprising all taxa sequenced by both the author of this study and Pridgeon, Solano & Chase (2001). Similar to the findings in the Cuban Analysis, the incomplete sequence of the two accessions of P. ghiesbreghtiana had a great influence on the topology. Trees containing the P. ghiesbreghtiana data showed partially distorted clades with many groupings being in discordance of even highly preserved morphological features, e.g. number of pollinia. This may be due to the fact that PAUP ignores those loci that contain missing values in any of the sequences (A. Pridgeon, pers. comm.) which would reduce the amount of phylogenetically informative sites by > 50%. Since the presentation of the results should not be separated from discussion, the trees are shown in the next chapter (Fig. 69, Fig. 70) for convenience.


Footnotes and Endnotes

1 Confirmed by Wright (in herb.) and Dod (1986b: 188)

2 Plants (Stenzel 1298) in cultivation showed self-pollinization: after 7-10 days the rostellar tissue began to produce mucus that connected the anther with the stigma. Ovaries began to swell and the perianth wilted rapidly.

3 However, pleurothallid orchids possess various substitutes for the lack of pseudobulbs: succulent leaves are the most common way to store water.



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