Coccothrinax yunquensis Borhidi & Muñiz

Henderson, Andrew, 2023, A revision of Coccothrinax, Hemithrinax, Leucothrinax, Thrinax, and Zombia (Arecaceae), Phytotaxa 614 (1), pp. 1-115 : 87-89

1.39. Coccothrinax yunquensis Borhidi & Muñiz in Muñiz & Borhidi (1981 publ. 1982: 447). Type:— CUBA. Prov. Guantánamo, caliza de la cumbre del Yunque de Baracoa , 500 m, 26 November 1978, A. Borhidi & P. Herrera 15279 (holotype HAC n.v., isotype BP n.v.). Plate 28

Stems not recorded. Leaves not recorded; leaf sheath fibers 1.8 mm diameter, stout, woody, loosely woven, the inner and outer layer combining at the apices to form erect , spine-like fibers; petioles 11.9(7.9–15.8) mm diameter just below the apex; palmans 10.4(9.0–11.8) cm long, relatively short, with the adaxial veins prominent and terminating in a slight raised ridge and distinct pulvinus; leaf blades not wedge-shaped; segments number not recorded, the middle ones 37.7(31.5–45.0) cm long and 3.3(2.3–4.0) cm wide; segments not pendulous at the apices, giving the leaf a flat appearance; middle leaf segments relatively short and broad, abruptly narrowed (shoulder) toward the apex, otherwise parallel-sided, often strongly folded, stiff and leathery, the apices briefly splitting; middle leaf segment apices blunt and rounded; leaf segments not waxy or sometimes with a deciduous, thin layer of wax adaxially, densely indumentose abaxially, with irregularly shaped, persistent, interlocking, fimbriate hairs, each one with a rounded, raised, light green to greenish-brown center, without poorly developed transverse veinlets. Inflorescences curving, arching, or pendulous amongst the leaves, with few to numerous partial inflorescences; rachis bracts somewhat flattened, loosely sheathing, usually tomentose with a dense tuft of erect hairs at the apex; partial inflorescences not recorded; rachillae 4.0 cm long; flowers not recorded; fruits not recorded.

Distribution and habitat:— Eastern Cuba (Guantánamo) ( Fig. 18 ), known only from El Yunque mountain, on calcareous rocks at 510(500–520) m elevation.

Taxonomic notes:— The type of Coccothrinax yunquensis has not been found at HAC ( Moya 2021). Leaf sheath fibers are scored as stout, woody, loosely woven, the layers combining at the apices to form erect , spine-like fibers. This is, however, not easy to score from the only specimen with leaf sheaths, but seems to agree with the protologue. Thus scored, C. yunquensis has a unique combination of qualitative character states and is recognized as a phylogenetic species. Although Muñiz & Borhidi (1981) considered that C. yunquensis was closely related to C. salvatoris , it appears more similar to C. orientalis , differing only in its leaf sheath fibers, and possibly to C. microphylla . Morici (1996) has given an illustrated account of C. yunquensis in its native habitat.

Imperfectly known species

Coccothrinax viridescens Noblick & Street in Noblick, Street & Barros (2019: 9). Type:— UNITED STATES. Florida, Miami-Dade county, Miami , Miami Zoo (Zoo Miami), 12400 SW 152 Street, parking lot near West B parking, 25˚36’43.9” N 80 ˚23’51.16”, 3.35 m, 8 December 2017, L . Noblick , A . Street & L . Danielson 5718 (holotype FTG!, isotypes F n.v., K n.v., MO n.v., NY n.v.)

Stems 3.0 m long and 7.5 cm diameter, solitary. Leaves more or less deciduous or only leaf bases persisting on stem; leaf sheath fibers not recorded; petioles 10.1 mm diameter just below the apex; palmans 26.5 cm long, relatively long, without prominent adaxial veins; leaf blades not wedge-shaped; segments number not recorded, the middle ones 4.0 cm long and 1.9 cm wide; segments not pendulous at the apices, giving the leaf a flat appearance; middle leaf segments relatively long and narrow, tapering from base to apex, scarcely folded, flexible and not leathery, a shoulder or constriction absent or poorly developed, the apices thin, splitting and breaking off; middle leaf segment apices attenuate; leaf segments not waxy adaxially, without tomentum abaxially, without well-developed transverse veinlets. Inflorescences curving, arching, or pendulous amongst the leaves, with few partial inflorescences along the rachis; rachis bracts somewhat flattened, loosely sheathing, usually tomentose; partial inflorescences 3; proximalmost rachillae straight, 8.0 cm long and 1.6 mm diameter in fruit; rachillae surface not recorded; stamens not recorded; fruit pedicels length not recorded; fruits 6.2 mm long and 6.2 mm diameter, purple-black; fruit surfaces smooth or sometimes with projecting fibers; seed surfaces deeply lobed, the lobes running from base of seeds almost to apices.

Distribution and habitat:— Known only from cultivated plants in Miami, Florida.

Taxonomic notes:— Coccothrinax viridescens is here considered to be an imperfectly known species because it occurs only in cultivation. Given the propensity of cultivated Coccothrinax species to hybridize ( Craft 2017), it may be of hybrid origin.

Figures

FIGURE 18. Distribution of C. spissa, C. torrida, and C. yunquensis.

PLATE 28. Coccothrinax yunquensis, Cuba, with relatively short palmans with the adaxial veins prominent and terminating in a slight raised ridge and distinct pulvinus, and leaf segments blunt and rounded at the apices. (Image by Raúl Verdecia Pérez).