S. Vietnam, Prov. Khanh Hoa, distr. Khanh Son, 42 km to NE from Dalat city. Primary closed broadleaved evergreen forest along bluffs of giant waterfall in upper reaches of Lieng Ly river on E macroslope of Hon Giao mt. ridge at 1300 m alt. (N 12° 12′, E 108° 44′). Shrub up to 2 m hg on open wet stream rocks. Flowers purple-violet. Common. VH 4297 24.04.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)