Raphiocarpus tonkinensis (Gesneriaceae), a new species from northern Vietnam.

Raphiocarpus tonkinensis, a new species of Gesneriaceae from Cuc Phuong-Ngoc Son-Pu Luong limestone range, northern Vietnam, is described and illustrated here. The new species is morphologically similar to R. axillaris and R. taygiangensis, but clearly differs from these two species in having asymmetrical leaves in a pair and a whorl of three, purplish white to pinkish white corolla with purple longitudinal lines and purple patches in the throat and at the bases of the lower lobes. A detailed morphological description together with color illustrations, information on phenology, distribution, ecology, preliminarily conservation assessment and comparison with its morphologically similar species are also provided.