Noteworthy Collections: DOMINICAN REPUBLIC

Abstract

Duranta arida Britt. & Wils. subsp. serpentina Sanders & Judd (VERBENACEAE)—Pedernales Province: Sierra de Baoruco National Park, accessed N of Cabo Rojo on old Alcoa road to Aceitillar, then north on jeep trail (Sendero Baoruco) to Caseta #2. Along trail between park entrance (near Caseta de Control, #4) and Caseta #2, on steep slope below location of sign pointing direction to ‘‘Caseta No. 2.’’ 1,850 m. High elevation pine forest. Lat. 18u12958.20N, Long. 71u34923.10W Datum: WGS84, 3 June 2006, Judd 8130 (FLAS, JBSD, NY). Significance. This collection represents the first documented occurrence of this distinctive subspecies of Duranta arida in the Dominican Republic, where it occurs in the Sierra de Baoruco, on steep rocky slopes in a high montane forest of Pinus occidentalis Sw. The taxon previously was known only from two collections (i.e., Judd 4931: FLAS, JBSD; Proctor 10740: US) in the Massif de la Selle, Haiti (Judd and Sanders 1986, Liogier 1994). The range extension is not really surprising, given that the Sierra de Baoruco, in the Dominican Republic, is the eastward extension of the Massif de la Selle. The habitats of the Haitian and Dominican collections are strikingly similar – both are from steep rocky, limestone slopes, in open forests dominated by Pinus occidentalis. Associated species in the Sierra de Baoruco include Baccharis myrsinites (Lam.) Pers., Chamaecrista selleana (Urb.) Britt. & Rose, Eupatorium illitum Urb., Fuchsia triphylla L., Garrya fadyenii Hook., Hypericum hypericoides (L.) Crantz, Ilex tuerckheimii Loes., Lyonia microcarpa Urb. & Ekman, Myrica picardae Krug & Urb., Pilea spp., and Senecio picardae Krug. & Urb. Associates at the type locality, near Pic la Selle, are similar (see list in Judd and Sanders 1986). The Haitian collections are from 2,000–2,550 m elevation, so the Dominican collection also slightly expands the elevational range of this taxon. This new collection of Duranta arida subsp. serpentina also expands the documented variation in leaf form. The collections from the Sierra de Baoruco have leaves with emarginate to truncate or rounded-mucronate apices, and often have two, small lateral teeth—and thus are often minutely tricuspidate. The leaves of the previously known collections of this subspecies are apically emarginate or tricuspidate. The leaves of plants of Duranta arida subsp. domingensis (Urb.) Mold., which is more widespread on Hispaniola (Liogier 1994), are usually acute to rounded-mucronate. The other distinctive features of D. arida subsp. serpentina, i.e., the prostrate habit, with the branches creeping along the ground (vs. erect stems to 2–3 m tall in subsp. domingensis) and the fruiting calyx open at the apex (vs. usually closed in subsp. domingensis), match those of the Massif de la Selle collections. Thus, the distinctiveness of subsp. serpentina, especially the extremely prostrate habit – with the stems growing along the ground in a snake-like fashion – allows it to be readily distinguished from subsp. domingensis (see keys in Judd and Sanders 1986, and Liogier 1994). Although Duranta arida subsp. domingensis does occur in the Dominican Republic, it was not seen in this part of the Sierra de Baoruco. It is noteworthy, however, that Duranta arida, without designation of subspecies, was included in a list of plants occurring in the Sierra de Baoruco (Garcia et al. 2001). The two subspecies likely are ecologically separated, and thus are probably reproductively isolated. This taxon was found during work on the systematics of Miconieae (Melastomataceae) in the Dominican Republic, and this fieldwork was supported by NSF Grant DEB-0515636. I thank Milciades Mejia and the herbarium *email address: wjudd@botany.ufl.edu Received July 2, 2007; Accepted August 21, 2007. CASTANEA 73(1): 40–41. MARCH 2008