N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Thang Loi, vicinities of Lung Sam village (N 22°45′ E 106°42′). Secondary wet evergreen broadleaved forest with remnants of primary elements on steep slopes and bluffs of karst remnant limestone ridge at 550-600 m elev. Lithophyte herb on open rocks and vertical cliffs of NW exposition. Flowers white with green center. Very common.
CBL 1678 24 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)