Type. Shrub 3 m, flowers white, occasional in woodland, southwest slopes of Ptai-i-tepui, Edo. Bolivar, Venezuela, alt. 1600-2000 m, 17 Dec 1952, Bassett Maguire & John J. Wurdack 33871 (holotype US 2342478). Paratype. VENEZUELA, Edo. Bolivar. Ptari-tepui: forested south-facing slopes on "Cave Rock," alt. 1810 m, Steyermark 59518.
In the typical subspecies (now known from Duida, Huachamacari, Guaiquinima, and the Chimanta Massif), the ovary apex is truncate and sparsely stellulate-furfuraceous, but with no trace of setae.