Monographs Details: Ceratostema
Authority: Maguire, Bassett. 1978. The botany of the Guayana Highland--part X. Mem. New York Bot. Gard. 29: 1-288.
Discussion:The genus Ceratostema as it is currently recognized consists of 17 species. They are distributed in the high Andes from southern Colombia to northern Peru, with 13 species being endemic to Ecuador. The genus was last treated by A. C. Smith (1952) where a brief discussion of its characteristics is given along with a key to the 16 species then recognized.
The exact generic limits of Ceratostema are still questionable, it being closely related to a group of genera including Ceratostema, Semiramisia, Oreanthes, Siphonandra, Gonocalyx, and Pellegrinia. The following is the first report of any species of the group mentioned above in Guayana. The new species is placed in the genus Ceratostema where it is seemingly most similar morphologically to the Ecuadorian C. nubigeneum.