Oncocalyx

Small shrubs, glabrous or with simple hairs and a single haustorial attachment. Flowers in clusters or 206 in an umbel with a very short peduncle. Corolla 5-merous, usually joined to less than halfway, opening with a V-shaped slit on one side, developing vents when mature; mostly yellow in colour, sometimes banded red and white or greenish; tube constricted above a basal swelling or narrow throughout; lobes linear, erect, recurved or revolute. Stamen filaments attached at base of corolla lobes or above. Berry obovoid, red, often with a persistent calyx.

Oncocalyx is a genus of flowering plants belonging to the family Loranthaceae.

Its native range is Ethiopia to Southern Africa, and the Arabian Peninsula.