Monographs Details: Tocoyena guianensis var. glabriuscula Steyerm.
Authority: Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
Description:Latin Diagnosis - A var. guianensis differt stipulis extus glabris apice subacutis vel subobtusis, corollae tubo 15 em longo, foliorum laminis subtus glabris axillis nervorum lateralium sparse pubescentibus et costa media sparse pubescenti exceptis, supra laminis glabris vel fere glabris.

Discussion:This taxon may have to be considered perhaps eventually as a species distinct from T. guianensis, because of its combination of shorter corolla-tube and lobes, glabrous shorter-pointed stipules, and mostly glabrate leaves. However, this conclusion cannot be made until more collections reveal the extent of variation existing in the length of the corolla-tube and degree of glabrity versus pubescence of the leaves and stipules. At present, it is apparent that transitions exist among the varieties of T. guianensis between a glabrate lower and upper leaf-surface to one more pubescent, as well as glabrate to pubescent lower and upper midribs. Also, the relative lengths of the corolla-tube may eventually show intergrading measurements between the varities considered in the present treatment.