Type: shrub or small tree 2-10 m, petals pale pink, anthers pale yellow, occasional among boulders on hillside, elev. 1750 m, Cerro Yutaje, Terr. Amazonas, Venezuela, Feb 17-19, 1953, Bassett Maguire & Celia K. Maguire 35289 (NY).
Typical G.sessilifolia, as represented on Roraima. Ilu-tepui, Ptari-tepui. and Chimanta-tepui, has white petals and ovary apex truncate without collar. On Auyan-tepui exists still another population with pink petals, persistent pubescence on the lower leaf-surface, and truncate ovary apex; this subspecies will be described at a later date. G. sessilifolia is quite variable in leaf size and degree of leaf venation development; the ovary and fruit may be either 2- or 3-celled.