This species is characterized by its medium-sized elliptic leaves, racemiform inflorescences with stiff peduncles and primary axes with a dozen or more flowers, reduced lobed involucels, pedicels 2.5-8.5 mm long, lobed calyx limbs, white to pink corollas with tubes 4-7 mm long and the lobes strongly reflexed, and winged pyrenes. The corolla tubes are shorter than the lobes.

Cortés-Ballén (2003) included only plants from the Guayana region in Retiniphyllum tepuiense, but later authors have also included plants from sandstone mountains in Ecuador in this species. The Ecuadorian material was not available to her during her study. No morphological differences are evident between the plants from these two areas, except the plants from Ecuador have corollas that reach a slightly larger size (tubes up to 8 mm, vs. up to 7.5 mm in the Guayana region).

Retiniphyllum tepuiense is similar to Retiniphyllum fuchsioides from Peru, which has developed bracts, pedicels 2.5-9 mm long, and deep pink to red corollas with tubes 16-25 mm long and longer than the lobes. Retiniphyllum tepuiense is also similar to Retiniphyllum maguirei of lowland areas in Suriname, which inflorescences with fewer than a dozen flowers and red to deep pink corollas with tubes 7-10 mm long.