A revision of Ornithoboea (Gesneriaceae)

The genus Ornithoboea C.B.Clarke (Gesneriaceae) from limestone habitats in Peninsular Malaysia, Thailand, Myanmar (Burma), Laos, Vietnam and Southern China is revised. It has 16 species, three of which are newly described: Ornithoboea maxwellii S.M.Scott from Thailand, Ornithoboea puglisiae S.M.Scott from Thailand and Ornithoboea obovata S.M.Scott from Vietnam. The plants are characterised by small, bilabiate flowers with a distinctive palatal beard on the lower lobes and a circlet of hairs around the mouth of the corolla tube. A key is provided, all species are described, and distribution maps and IUCN conservation assessments are given for all species.