New Species of Sapranthus B. C. Seemann and Unonopsis R. E. Fries (Annonaceae) from Mesoamerica

Abstract

Two new species of Annonaceae, Sapranthus viridiflorus G. E. Schatz and Unonopsis stevensii G. E. Schatz, are described from Mesoamerica. Color photographs of the new species can be accessed over the World Wide Web by searching the name in WZTROPICOS at http://www.mobot.org/ Pick/Search/pick.html. RESUMEN. Se decriben dos especies nuevas de Annonaceae, Sapranthus viridiflorus G. E. Schatz y Unonopsis stevensii G. E. Schatz, de Mesoambrica. Fotograffas a color de las especies nuevas son accesibles buscando el nombre en las piginas de Internet de WZTROPICOS en la siguiente direcci6n: http://www.mobot.org/Pick/Search/pick.html. In anticipation of the upcoming publication of the Flora de Nicaragua, I provide here names and descriptions for two undescribed species of Annonaceae from Mesoamerica. Sapranthus viridiflorus G. E. Schatz is the southernmost of seven species in a genus extending from the states of Sinaloa and Veracruz, Mexico, to the province of Los Santos, Panama. In contrast to the other species of Sapranthus B. C. Seemann, which occur in seasonally dry deciduous forest and possess membranaceous reddish to deep purple petals with evident venation, S. viridflorus occurs in moist to wet evergreen forest and exhibits thick, fleshy green petals lacking venation at maturity. Unonopsis R. E. Fries is a genus of ca. 40 species distributed from Belize to Bolivia in wet, evergreen forest, with 6 species currently known from Mesoamerica, and an additional 4-5 new species awaiting description. Although not yet known from Nicaragua, Unonopsis stevensii G. E. Schatz is to be expected in the southeastern region of the country along the Rio San Juan just to the north of Cerro Coronel and Barra del Colorado in Costa Rica, the sole locality for the new species. Sapranthus viridiflorus G. E. Schatz, sp. nov. TYPE: Costa Rica. Heredia: La Selva Biological Station of the Organization for Tropical Studies, 4 km S of Puerto Viejo de Sarapiqui, 10026'N, 84001'W, 35 m, 15 Feb. 1984 (fl), G. E. Schatz 963 (holotype, MO; isotypes, CR, WIS). Figures 1, 2, and http://hoya.mobot.org/ mobot/research/image/01602308O001.jpg, http: //hoya. mobot. org/mobot/research/image/ 01602308002.jpg A speciebus aliis Sapranthi petalis enervibus carnosis viridibus et carpellis 2-5 differt. Tree to 12 m tall, the young branches brownish gray tomentose. Leaves membranaceous, the petiole 0.4-1.0 cm long, shallowly canaliculate, brownish gray tomentose; lamina elliptic to oblong-obovate, 5.6-29.8 cm long, 2.7-12.1 cm broad, the base cuneate to rounded and somewhat truncate, the apex acuminate to cuspidate, the upper lamina surface sparsely white velutinous, the lower surface white velutinous, the margins finely ciliate; venation weakly brochidodromous with 8-15 lateral veins per side, the midrib slightly impressed and densely white velutinous above, especially toward the base, prominently elevated and short white hirsute below, drying purplish black, the slender lateral veins elevated and short white hirsute below. Flowers solitary, pendent, terminal but appearing leaf-opposed (or rarely cauliflorous and borne on older wood), with a fruity fragranice, albeit with a slightly fetid component; pedicel 1.0-1.7 cm long, sparsely tomentellous, bearing a lanceolate-ovate to rounded bract near the base to 0.8 cm from the base, 0.50.9 cm long, 0.3-0.5 cm broad, the apex acute to obtuse, the base decurrent along the pedicel, the margins revolute. Sepals triangular, 0.7-0.8 cm long, 0.5-0.7 cm broad, the apex acute, slightly reflexed, the base truncate, tomentellous outside. Petals 6, in 2 subequal imbricate whorls, membranaceous and with venation evident in bud, becoming fleshy and lacking any evident venation at anthesis when fresh, revealing faint venation when NovoN 8: 436-440. 1998. This content downloaded from 207.46.13.128 on Wed, 07 Sep 2016 05:04:21 UTC All use subject to http://about.jstor.org/terms Volume 8, Number 4 Schatz 437 1998 New Species of Annonaceae ,,? ?r:: ~ r. r r??