Coccothrinax jimenezii Mejía & García (2013: 9)

Henderson, Andrew, 2023, A revision of Coccothrinax, Hemithrinax, Leucothrinax, Thrinax, and Zombia (Arecaceae), Phytotaxa 614 (1), pp. 1-115 : 56

1.20. Coccothrinax jimenezii Mejía & García (2013: 9) . Type:— DOMINICAN REPUBLIC. Province Independencia, Sierra de Neiba , 9 km al oeste de Postrer Río, carrertera hacia La Descubierta, lado norte del Lago Enriquillo, 18˚34’ N 71 ˚42’ W, 50 m, 24 July 2010, R. García & M. Mejía 7640 (holotype JBSD!). Plate 15

Stems 4.0(2.5–5.5) m long, diameter not recorded, solitary or clustered. Leaves more or less deciduous or only leaf bases persisting on stem; leaf sheath fibers 0.4(0.2–0.7) mm diameter, stout, loosely woven and forming a loose, hexagonal mesh, initially forming ligules at the apices; petioles 7.6(6.2–10.0) mm diameter just below the apex; palmans 4.4(1.5–8.0) cm long, relatively short, with the adaxial veins prominent and terminating in a slight raised ridge and distinct pulvinus; leaf blades wedge-shaped; segments 23(16–29) per leaf, the middle ones 36.1(30.0–45.0) cm long and 1.9(1.7–2.2) cm wide; segments not pendulous at the apices, giving the leaf a flat appearance; middle leaf segments tapering from base to apex, often folded, stiff and leathery, with or without scarcely developed shoulders, the apices sharply pointed and briefly splitting; middle leaf segment apices attenuate; leaf segments not waxy or sometimes with a deciduous, thin layer of wax adaxially, without indumentum, scales, or wax abaxially, without or with poorly developed transverse veinlets. Inflorescences curving, arching, or pendulous amongst the leaves, with few partial inflorescences; rachis bracts narrow, closely sheathing, sparsely tomentose, usually without hairs at the apex; partial inflorescences 4; proximalmost rachillae straight, 5.2(3.0–7.7) cm long and 0.8(0.5–1.0) mm diameter in fruit; rachillae uneven at or near anthesis with lines of warty outgrowths, these often becoming more pronounced as fruits develop; stamens not recorded; fruit pedicels 0.6(0.3–1.1) mm long; fruits 5.1 mm long and 5.6 mm diameter, yellowish; fruit surfaces smooth or sometimes with projecting fibers; seed surfaces lobed, the lobes running from base of seeds approximately to equator.

Distribution and habitat:— Dominican Republic (Independencia) ( Fig. 13 ) in dry forest on limestone rocks and coral sediments, or dry, broad leaf forest, at 161(0–500) m elevation.

Taxonomic notes:— As a preliminary species, Coccothrinax jimenezii has a unique combination of character states and is recognized as a phylogenetic species. It is a member of a group of nine Hispaniolan species (see notes under C. boschiana ). An unidentified specimen (Zanoni 33375) from near Pestel in southwestern Haiti shares all character states (although lacking fruits) with C. jimenezii . However, it occurs almost 250 km west of the type locality of C. jimenezii and on biogeographic grounds it seems likely to represent a different taxon.

Subspecific variation:—There is some local variation and there appear to be three populations. Five of the seven known specimens are from 0–50 m elevation on the margins of Lago Enriquillo, the type locality, in dry forest on limestone. Here the population is very small, and plants appear to have clustered stems. Another specimen (Zanoni 39724) occurs in a nearby locality at 500 m elevation and is said to grow in “bosque latifoliado medio seco”. This specimen has a longer palman, more, longer segments, and longer pedicels than the specimens from the type locality. One other specimen (Montero s.n.) has been collected from a large population approximately 20 km due west of the type locality. This specimen has a solitary stem and thicker leaf sheath fibers.

Figures

FIGURE 13. Distribution of Coccothrinax gracilis, C. gundlachii, C. hioramii, and C. jimenezii

PLATE 15. Coccothrinax jimenezii, Dominican Republic, with clustered stems and wedge-shaped leaf blades. (Image by Eladio Fernández).