Coccothrinax samanensis Henderson,Montero&Bacon

Henderson, Andrew, 2023, A revision of Coccothrinax, Hemithrinax, Leucothrinax, Thrinax, and Zombia (Arecaceae), Phytotaxa 614 (1), pp. 1-115 : 75-78

1.33. Coccothrinax samanensis Henderson,Montero&Bacon in Henderson et al. (2023: 110). Type:— DOMINICAN REPUBLIC. Provincia Samaná, Distrito Municipal Las Galeras , Punta Balandra , carretera Samaná-Las Galeras , a 3.2 km después del hotel Bahía Príncipe , 19º10’N 69º14’W, 30 March 2022, O. Montero, T. Clase, M. Novas, J. Huranga & P. Toribio 528 (holotype JBSD!, isotype NY!). Plate 22

Stems 2.0 m long, diameter not recorded, solitary. Leaves more or less deciduous or only leaf bases persisting on stem; leaf sheath fibers 0.5 mm diameter, stout, loosely woven and forming a loose, hexagonal mesh, initially forming ligules at the apices; petioles 8.0(6.4–9.6) mm diameter just below the apex; palmans 10.0(7.6–12.0) cm long, relatively short, with the adaxial veins prominent and terminating in a slight raised ridge and distinct pulvinus; leaf blades wedge-shaped; segments 26(23–29) per leaf, the middle ones 50.5(50.0–51.0) cm long and 2.5(1.9–2.9) 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, densely indumentose abaxially, with irregularly shaped, semi-persistent, interlocking, fimbriate hairs without an obvious center, 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, 4.9(4.0–5.8) cm long and 1.5 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 0.2 mm long; fruits 3.0 mm long and 4.5 mm diameter, color not recorded; fruit surfaces densely muricate; seed surfaces lobed, the lobes running from base of seeds approximately to equator.

Distribution and habitat:— Northeastern Dominican Republic (Samaná) on the eastern end of the Peninsula de Samaná ( Fig. 17 ) in arid areas on limestone terraces or cliffs at 50 m elevation.

Taxonomic notes:— As a preliminary species, Coccothrinax samanensis 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 ), sharing with other species in the group curved stems. It is distinguished from most other species in this group by its densely muricate fruit surfaces. It shares this character state with three other species, C. boschiana and C. ekmanii from Hispaniola and C. munizii from Cuba. Coccothrinax samanensis is also unusual in that its seeds are scarcely lobed and could almost be scored as smooth or shallowly lobed, and the endosperm is effectively homogeneous.

Coccothrinax samanensis occurs in three populations (Cabo Samaná, Cabo Cabrón, Punta Balandra). No specimens from Cabo Cabrón have been seen, but this population is illustrated in Fernández & Gottschalk (2017, pages 138–141, as C. gracilis ). These images show taller plants with slender, clean, curved stems and apparently wedge-shaped leaves, and shorter plants with thicker, straight stems covered with leaf sheath bases and more orbicular leaves. Eladio Fernández (pers. comm.) reports that C. samanensis also occurs at La Guacima, between Cabo Samaná and Punta Balandra.

Figures

FIGURE 17. Distribution of Coccothrinax samanensis, C. saxicola, C. scoparia, and C. spirituana.

PLATE 22. Coccothrinax samanensis, Dominican Republic, with slender, clean, curved stems and wedge-shaped leaves. (Image by Eladio Fernández).