Monographs Details: Ambelania oleaefolia var. riparia 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.
Family:Apocynaceae
Description:Latin Diagnosis - Haec varietas a var. oleaefolia statura altiore 3-6 m alta et foliis latioribus 2-4.5 cm latis recedit

Distribution and Ecology - VENEZUELA: Amazonas: frequent along Caño Pimichin between Rio Guainia and Pimichin, alt. 30-140 m; tree 3-6 m, flowers white; 2 Jul 1959, J. J. Wurdack & L. S. Adderley 43.J79 (holotype, NY). Occasional along Caño Yapacana, alt.-125 m; shrub 3-5 m, flowers white, fruit green; 17 Jun 1959, Wurdack & Adderley 43021 (paratype, NY).

Discussion:Differs from the savanna var. oleaefolia Monachino in its greater height, 3-6 m (instead of 0.2-0.8; "2 m " in Maguire et al. 30553), and broader leaves, 2-4.5 cm wide (instead of 0.7-3 cm). The corollas in our specimens are larger, the tube being 2.5-3 cm long, the lobes about 3 cm long, 8-12 mm wide. The stamens are inserted about 7 mm from the base of the tube, the anthers are 5.8 mm long. The habitat is riparian.