Monographs Details: Prestonia acutifolia (Benth. ex Müll.Arg.) K.Schum.
Authority: Maguire, Bassett & Wurdack, John J. 1958. The botany of the Guayana Highland--Part III. Mem. New York Bot. Gard. 10: 1-156.
Family:Apocynaceae
Description:Distribution and Ecology - Colombia: Marguire & Wurdack 34991, Rio Negro, along river between Piedra Cucuy and Santa Rosa, elev. 100 m, Apr 11, 1953, woody vine, flowers pale yellow. VENEZUELA: Amazonas: Maf/uire, Wurdack & Bunting 36101, Great Rapids of the Orinoco, in low moist savanna near Palomal, near river 15 km south of Pto. Ayacucho, 100-120 m elev., Nov 9, 1953, vine in low shrubs, flowers sulphur yellow. Maguire, Wurdack & Bunting 37529, Casiquiare, occasional along Rio Yatua near Laja Catipan, 100-140 m, Feb 6, 1954, vine climbing on low trees, flowers sulphur yellow, the throat ring whitish with 5 orange bars. Bolivar: Wurdack & Monacliino 39870, Rio Orinoco, occasional in Isla Sta. Elena, opposite mouth of Rio Pargueni, elev. 80-90 m, Dec 13, 1955, plant without latex, flowers pale yellow. Wurdack & Monachino 39976 Rio Orinoco, Laja Caruto, east bank of river just below Raudal Marimare, elev. 80-90 m, Dec 18, 1955, herbaceous vine on shrubs, latex none, corolla pale greenish yellow. BRAZIL: Cowan 38279, Serra do Navio, Amapa, Rio Amapari, forested slopes of Observatorio Ore Body, ca. 275 m alt., Nov 12, 1954, vine over secondary growth, flowers pale yellow, fruit green.

Discussion:The first three collections cited above have the leaves of a firmer texture than is usual for the species, suggesting P. cayennensis (A. DC.) Pichon. The anthers are glabrous on the back, not reaching up to the faucal annulus; the epistaminal appendages are short. The mericarps (34991, 37529) are, as in P acutifolia, typically agglutinated and puberulent, unlike those of P. cayenne nsis. P. acutifolia, as interpreted at the present time, has a vast range, extending from Central America or Mexico to Argentina. It is quite variable, and its limits of morphological variation are not clearly defined. There is a likelihood that it will eventually be submerged in P. qninquangularis (Jacq.) Spreng., for the characters invoked to separate the two are not too convincing. Incidentally, the NYBG sheet (flowers poor, corolla lacking) of Maguire & Fanshawe 23351 from the Kaieteur Plateau in British Guiana, cited as P. perplex a Woods, in Bull. Torrey Club 75: 556 (1948), appears to be P. cayenne nsis. In previous works, Echitcs leptoloba Stadelm., originally described from the Rio Negro in Brazil, has been curiously placed in the synonymy of P agglutinata (Jacq.) Woods., an Haitien species that has never been reported from South America. The description of Stadelmeyer's species better suggests P. acutifolia.
Distribution:Colombia South America| Venezuela South America| Brazil South America|