Monographs Details: Lacmellea pygmaea var. latifolia Monach. & Monach.
Authority: Maguire, Bassett & Wurdack, John J. 1961. The botany of the Guayana Highland--part IV (2). Mem. New York Bot. Gard. 10: 1-87.
Description:Latin Diagnosis - Haec varietas a var. pygmaea foliis lanceolatis vel oblongis latioribus 1-3 cm latis recedit.
Distribution and Ecology - VENEZUELA: Amazonas: locally abundant in Sabana Cumare on right bank of Caño Cumara, Rio Atabapo, 20 km above San Fernando de Atabapo, alt. 125 m; shrub 0.2-1 m, with abundant milky latex, flowers white, fruit green; 3 Jun 1959, J. J. Wurdack & L. S. Adderley 42757 (holotype, NY). Occasional in Sabana El Yenado, left bank of Caño Pimichin above Pimichin, alt. 140 m; shrub 0.2-0.4 m, flowers cream; 2 Jul 1959, Wurdack & Adderley 43291 (paratype, NY).
Differs from var pygmaea Monachino in its lanceolate or oblong, much broader leaves, 1-3 cm wide (instead of less than 0.5 cm). The flowers in our specimens are somewhat larger; corolla-tube 13 mm long, anthers 4.6 mm and style 2 mm long.
A. pygmaea is known from only the Alto Rio Orinoco. The typical variety with very narrow leaves was found in March, a drier month than June-July when var. latifolia was collected. It is unknown what the seasonal or local ecological effects on the gross morphology of the plant may have been. Such qualms are also entertained regarding the new variety proposed in the beginning of the present treatment of the Apocynaceae, Ambelania oleaefolia var. riparia, which is likewise distinguished chiefly on size differences.