Two New Species of Chamaedorea (Arecaceae)

Abstract

Chamaedorea ponderosa from Panama and C. christinae from Colombia are named and described as new, and compared with related taxa. Chamaedorea includes over 100 species of small, dioecious, pleonanthic, understory palms restricted to neotropical, mostly moist or wet, primary rain and cloud forests from eastern and western Mexico to northern Bolivia. The genus is most diverse in wet mountain forests from 800 to 1500 m elevation. The mountainous area of southern Mexico and adjacent Guatemala is the primary center of distribution; a secondary center is the mountainous area shared by Costa Rica and Panama. Since the publication of a monograph of Chamaedorea (Hodel, 1992a) and subsequent articles adding several new species (Hodel, 1992b, 1995, 1996; Hodel et al., 1995), further study has enabled me to name and describe two new species. Chamaedorea ponderosa Hodel, sp. nov. TYPE: Panama. Darien: Cerro Pirre, 2-3 mi. N of summit, 7056'N, 77042'W, 1000-1100 m, 31 Dec. 1978, Hartman 8529 (pistillate) (holotype, MO 3233713). Subgeneris Chamaedoreae (Martius) H. A. Wendland. C. murriensi Galeano affinis sed habitu grandiore, foliis nervis pluribus, inflorescentiis rhachidibus longioribus, petalis et sepalis nervis valde prominentibus, floribus masculinis dense positis, fructibus aurantiacis differt. Solitary, slender, understory palmlet to 2-4 m tall. Stem 2-2.5 cm diam., ringed, internodes 4-5 cm. Leaves simple and bifid, sometimes irregularly pinnate then usually with large terminal lobes and smaller basal pinnae, drying dark olive-green with a heavy, thick, bulky appearance; leaf base 25-30 cm long, obliquely long-open apically, tubular in basal 20-25 cm, longitudinally striated with a raised costa extending from petiole for 5-8 cm; petiole 18-35 cm long, 6-8 mm diam. at apex, 8-10 mm diam. at base, rounded and lighter green abaxially, flattened but becoming channeled toward base adaxially, longitudinally striated; rachis 40-50 cm long in simple blades, 40-60 cm long in pinnate blades, rounded and lighter green abaxially, angled and lighter green adaxially; simple blades 75 x 45-50 cm, incised apically 25 cm, acute-acuminate, with 20 elevated, sharply angled, primary nerves adaxially, these elevated abaxially, spaced 2 cm apart, 2-3 secondaries between each pair of primaries, secondaries not too conspicuous adaxially, 1-2 tertiary nerves abaxially between each pair of secondaries or a secondary and a primary, ne ves of lesser orders numerous, faint, all nerves lighter colored and except for primaries more conspicuous abaxially; pinnate blades 80-90 x 45-50 cm, pinnae 2-8(-16) per side, terminal pair to 3045 x 10-15 cm, basal pinnae 30-45 X 2.5-5.5 cm, sigmoid, falcate, long-acuminate, variously nerved depending on width but in same pattern as above. Inflorescences 50-75 cm long; peduncle 40-55 cm long, 1-1.5 cm wide at base, 3-5 mm diam. at apex; bracts 5-7, prophyll 2-4 cm long, 2nd bract 10 cm long, 3rd 25 cm long, 4th 35 cm long, 5th 15 cm long and exceeding peduncle and concealing a smaller 6'h bract to 5 cm long, bracts brown in flower, becoming tattered in fruit, obliquely open apically, longitudinally striated, basal bracts acute-acuminate, apical ones long-acuminate; rachis 12-17 cm long; staminate rachillae 931, these 25-40 cm long, 1-1.5 mm diam., drooping; pistillate rachillae 13-28, mostly simple but a few basal ones furcate, 18-25 cm long, 1.5-2 mm diam., ? spreading, peduncle and rachillae orange in fruit. Staminate flowers in ? dense spirals 2-3 mm apart, ? superficial, leaving elliptic scars 1.25-1.5 mm long, flowers in bud 2 x 2-2.75 mm; calyx 1 X 2-2.75 mm, deeply lobed 2/3 to base, prominently nerved, sepals connate in basal /3, broadly rounded apically, acute; petals 2 X 1.752 mm, ovate, valvate, acute, connate briefly basally and apically and there adnate to pistillode, corolla opening by lateral slits, prominently nerved; stamens 6, anthers 1 mm long, dorsifixed near base, filaments 0.5 mm long; pistillode 1.5 mm tall, columnar. Pistillate flowers in lax spirals 4-10 mm apart, ? superficial, leaving elliptic scars 1.75 mm long; flowers just past anthesis 2 X 3 mm; calyx 1 X 3 mm, cupular, moderately lobed, prominently nerved, sepals imbricate and/or connate in basal 12, broadly rounded apically; petals 2.5 x 3 mm, broadly obovate-spatulate, prominently nerved, imbricate in basal 3/4, rounded apically; pistil 2 X 2.5 NovoN 7: 35-37. 1997. This content downloaded from 157.55.39.181 on Thu, 29 Sep 2016 06:16:32 UTC All use subject to http://about.jstor.org/terms