A revision of Coccothrinax, Hemithrinax, Leucothrinax, Thrinax, and Zombia (Arecaceae) Author Henderson, Andrew text Phytotaxa 2023 2023-09-19 614 1 1 115 http://dx.doi.org/10.11646/phytotaxa.614.1.1 journal article 10.11646/phytotaxa.614.1.1 1179-3163 8389307 1.21. Coccothrinax landestoyii Henderson, Fernández & Bacon in Henderson et al. (2023: 108) . Type :— DOMINICAN REPUBLIC . Cordillera Central , Parque Nacional Francisco Alberto Caamaño , Provincia Azua , Municipio Las Charcas , 18°28’N 70°34’W , 243 m , 26 January 2022 , T . Clase, M . Landestoy & E . Fernández 12637 ( holotype JBSD !, isotype NY !). Plate 16 . Stems 3.7(3.0–4.0) m long, diameter not recorded, solitary. Leaves more or less deciduous or only leaf bases persisting on stem; leaf sheath fibers 1.3(1.1–1.5) mm diameter, stout, woody, loosely woven, ± joined or briefly free at the apices; petioles 7.4(6.7–8.7) mm diameter just below the apex; palmans 2.6(1.4–3.3) cm long, relatively short, with the adaxial veins prominent and terminating in a slight raised ridge and distinct pulvinus; leaf blades wedge-shaped; segments 27(25–30) per leaf, the middle ones 42.2(37.5–51.0) cm long and 2.0(1.6–2.4) 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 to numerous partial inflorescences; rachis bracts narrow, closely sheathing, sparsely tomentose, usually without hairs at the apex; partial inflorescences number not recorded; proximalmost rachillae straight, 6.0(5.0–7.0) cm long and 1.0(0.8–1.1) mm diameter in fruit; rachillae at or near anthesis not recorded; stamens not recorded; fruit pedicels 0.3(0.1–0.4) mm long; fruits 6.0(5.6–6.3) mm long, 6.0(5.8–6.1) mm diameter, yellowish-green; 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 ( Azua ) ( Fig. 14 ) in dry forest on limestone rocks at 268(243– 317) m elevation. Taxonomic notes:— As a preliminary species, Coccothrinax landestoyii has a unique combination of qualitative character states and is recognized as a phylogenetic species. It is a member of a group of nine Hispaniola species (see notes under C. boschiana ). In this group it appears most similar to C. boschiana in its stout, woody leaf sheath fibers, differing from that species in its non-muricate fruits. The fruits appear to be yellowish-green when ripe, and the lobes of the seeds run from the base approximately to the equator.