Coccothrinax boschiana Mejía & García (1997: 1),

Henderson, Andrew, 2023, A revision of Coccothrinax, Hemithrinax, Leucothrinax, Thrinax, and Zombia (Arecaceae), Phytotaxa 614 (1), pp. 1-115 : 39

1.8. Coccothrinax boschiana Mejía & García (1997: 1) . Type:— DOMINICAN REPUBLIC. Prov. Azua, Sierra Martín García, 5 km al sureste de Barrero, 18˚17’ N 70 ˚54’ W, 50 m, 15 November 1995, R. García, M. Mejía & S. Rodríguez 6059 (holotype JBSD!, isotypes B n.v., MAPR n.v., NY!, S n.v., S image!, US!). Plate 8

Stems 6.5(4.0–10.0) m long and 6.8(6.5–7.0) cm diameter, solitary. Leaves more or less deciduous or only leaf bases persisting on stem; leaf sheath fibers 1.5(1.1–1.9) mm diameter, stout, woody, loosely woven, ± joined or briefly free at the apices; petioles 11.4(7.0–15.4) mm diameter just below the apex; palmans 17.2(3.6–29.0) 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 28(19–37) per leaf, the middle ones 54.7(34.0–67.5) cm long and 3.3(1.9–4.2) 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 with a persistent, dense, whitish 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 partial inflorescences; rachis bracts narrow, closely sheathing, sparsely tomentose, usually without hairs at the apex; partial inflorescences 4(2–5); proximalmost rachillae straight, 4.9(3.3–7.7) cm long and 0.9(0.4–1.2) mm diameter in fruit; rachillae uneven at or near anthesis with lines of warty outgrowths, these often becoming more pronounced as fruits develop; stamens 7–8; fruit pedicels 0.1 mm long; fruits 5.5(5.0–6.2) mm long and 5.5(4.7–5.8) mm diameter, rose-red or red-purple; fruit surfaces densely muricate; seed surfaces lobed, the lobes running from base of seeds approximately to equator.

Distribution and habitat:— Dominican Republic (Azua) on the Sierra Martín García ( Fig. 10 ) in dry forest on dog’s tooth limestone at 89(30–200) m elevation.

Taxonomic notes:— As a preliminary species, Coccothrinax boschiana has a unique combination of qualitative character states and is recognized as a phylogenetic species. It appears similar to a group of eight other species ( C. concolor , C. ekmanii , C. gonaivensis , C. gracilis , C. jimenezii , C. landestoyii , C. montgomeryana , C. samanensis ) all endemic to Hispaniola. The Cuban C. munizii may also belong to this group. All these species are narrow endemics and often occur in arid, exposed, coastal areas on mogotes and/or dog’s tooth limestone. They usually have narrow, often flexible stems, stout leaf sheath fibers, relatively small leaves, short palmans with prominent adaxial veins and pulvini, relatively few segments, small inflorescences with short rachillae, and small fruits that are often depressed globose in shape. The small seeds are usually only shallowly lobed. Several of these species are very similar to one another and difficult to distinguish. However, since they all have narrow distributions with non-overlapping ranges they can easily be identified from locality alone.

Subspecific variation:—There appear to be two populations of Coccothrinax boschiana . Two specimens (Zanoni 32201, Veloz 816) are from a slightly different locality and a higher elevation (175–200 m) than the others, and have markedly smaller leaves than other specimens. The other five specimens known, including the type, are from lower elevations (30–77 m) near the sea and have markedly larger leaves. This population is also illustrated in Fernández & Gottschalk (2017, pages 118–119). There are too few specimens to test for differences between the two populations.

Apart from variation between populations, there is also variation within populations. Some plants have tall, thin, flexible stems, without a covering of persistent leaf bases, and these stems curve or twist. In the same population are plants with noticeably thicker, shorter, straight stems covered with persistent leaf sheath bases. These two stem types may be a result of age and/or exposure to prevailing winds. The thin, curved or twisted stems, in this and other species, may be caused by hurricanes. They are illustrated in Fernández & Gottschalk (2017, pages 114–115).

Figures

PLATE 8. Coccothrinax boschiana, Dominican Republic, with leaf bases persisting on stem and stout, woody, loosely woven leaf sheath fibers. (Image by Eladio Fernández).

FIGURE 10. Distribution of Coccothrinax baracoensis, C. bonettiana, C. borhidiana, and C. boschiana.