Oreocharis sihuiensis (Gesneriaceae), a critically endangered new species from Guangdong Province, China.

Oreocharis sihuiensis sp. nov. (Gesneriaceae) is described from Guangdong Province, China. Morphologically, the flower shape of this new species is similar to that of O. dayaoshanioides, but it can be distinguished by its leaf blade being adaxially densely pubescent, with hairs 0.2-0.5 mm long (vs. adaxially sparsely villous to villous, with hairs longer than 1 mm), lobes of the corolla upper lip subrounded and apex rounded (vs. broadly ovate to orbicular-ovate and apex acute), 3 staminodes (vs. absent or 2), disc margin cleft (vs. subentire), shorter filaments (ca. 6.0 mm long vs. 8.0-12.0 mm long), and shorter capsules (ca. 1.0 cm long vs. ca. 2.0 cm long). Considering its scarce number of individuals, and the presence of severe human disturbance, we preliminarily assess the new species as 'Critically Endangered' (CR) according to IUCN Red List Categories and Criteria.