New Rubiaceae from Venezuela

Abstract

Four new species of Rubiaceae are described from Venezuela: three from Territorio Federal Amazonas (Guettarda leiantha, Psychotria davidsae, Psychotria plowmanii), and one from Estado Zulia (Hillia zuliaensis). One variety is described from Estado Yaracuy (Psychotria aubletiana var. villipila). These new taxa have resulted from a joint project of exploration in Venezuela under a grant to the Missouri Botanical Garden by the National Science Foundation and to the Division of Biological Investigations, National Park Institute, Herbario Nacional of Caracas, Venezuela by CONICIT (Consejo Nacional de Investigaciones Cientificas y Tecnol6gicas). Since 1977 the Missouri Botanical Garden, recipient of a grant from the National Science Foundation of the United States, and the Herbario Nacional of Venezuela, recipient of a similar grant from the equivalent organization of Venezuela (CONICIT), have been conducting joint botanical explorations into various portions of Venezuela to make inventories of the flora in those areas previously unexplored, especially where changes might be forthcoming due to the construction of dams, drainage projects, or agricultural and lumbering activities. These explorations have resulted in a large number of additions to the known flora of Venezuela, as well as a considerable assemblage of undescribed taxa. In the present paper a few taxa of undescribed Rubiaceae are presented. Guettarda leiantha Steyerm., sp. nov. TYPE: Venezuela. Amazonas: along road between Paso El Diablo and Cafio de Culebra, 25-30 km SE of Puerto Ayacucho, 100m, 12 May 1980, Steyermark, Davidse & Guanchez 122318 (holotype, VEN; isotype, MO). Arbor 5-metralis, ramis glabris; foliis petiolatis, petiolis 1-2 cm longis modice crispato-pilosis; laminis elliptico-ovatis apice acuminatis basi acutis 12-17 cm longis, 5.5-7.5 cm latis, subtus praeter axillas barbellatas atque nervos breviter crispato-villosulos glabris, supra costa media sparse vel modice adpresso-pilosula aliter glabris, nervis lateralibus utroque latere ca. 7 tenuibus adscendentibus ante marginem 3-4 mm anastomosantibus; inflorescentia semel dichotoma, quoque ramulo inflorescentiae 8-15-flora semel vel non nihil dichotoma; pedunculo tenui 4-5 cm longo, 0.5 mm lato modice minute crispato-pilosulo; floribus tetrameris; calyce hypanthioque 1.5 mm longis, hypanthio 1 mm longo, 0.8 mm lato glabro, lobis calycis paullo inaequalibus suborbiculari-ovatis obtusis 0.30.4 mm longis, 0.3-0.4 mm latis sparsim ciliolatis; corolla tenuiter hypocraterimorpha 10 mm longa, tubo 8 mm longo, 1 mm lato extus glabro intus basi annulo denso piloso instructo inde 5 mm sparsim piloso, lobis ovali-oblongis apice rotundatis 1.5 mm longis, 1.5 mm latis, uno vel duobus lobis parce crenulatis intus marginibus papillatis extus glabris; antheris linearibus 2.7 mm longis in parte tertia superiore insertis; stylo 9 mm longo glabro. Tree 5 m tall, branches glabrous. Leaves petiolate, petioles 1-2 cm long, moderately crisppilose; leaf-blades elliptic-ovate, acuminate at apex, acute at base, 12-17 cm long, 5.5-7.5 cm wide, sparsely to moderately appressed-pilosulous above on midnerve, elsewhere glabrous, leaf axils beneath slightly barbellate, shortly crispvillosulous on main and secondary nerves, glabrous on surface, lateral nerves ca. 7 each side, slender. Inflorescence with 2 primary axes either not forked or once-forked, each fork bearing 815 flowers; peduncle slender, 4-5 cm long, 0.5 mm thick, moderately minutely crisp-pilosulous; flowers tetramerous; calyx and hypanthium 1.5 mm long, hypanthium 1 mm long, 0.8 mm wide; calyx lobes slightly unequal, suborbicularovate, obtuse, 0.3-0.4 mm by 0.3-0.4 mm, sparsely ciliolate; corolla slenderly hypocrateriform, 10 mm long, the tube 8 mm long, 1 mm broad, glabrous without, sparsely pilose in the basal 5 mm within with a dense pilose ring at the very base, lobes oval-oblong, rounded at apex, 1.5 mm by 1.5 mm, glabrous without, papillate within on margins, 1 or 2 of the lobes inconspicuously crenulate; anthers linear, included, 2.7 mm long, inserted in the uppermost 1/3 of tube; filaments 0.5 mm long; style filiform, 9 mm long, glabrous; fruit not seen. ' Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166. ANN. MISSOURI BOT. GARD. 71: 1175-1179. 1984. This content downloaded from 157.55.39.112 on Wed, 07 Sep 2016 04:51:30 UTC All use subject to http://about.jstor.org/terms 1176 ANNALS OF THE MISSOURI BOTANICAL GARDEN [VOL. 71 This taxon is allied to G. acreana Krause and G. ulei Krause, from which it may be distinguished by the completely glabrous exterior of the corolla, glabrous hypanthium, inflorescence with only two slender primary axes either once or not at all forked, and glabrous lower surface