N. Vietnam, prov. Cao Bang, distr. Nguyen Binh, municipality Ca Thanh (N 22°44′ E 105°50′). Primary semideciduous mixed forest along tops of remnant karst limestone ridge at 1350-1400 m elev. Terrestrial herb among shady rocks. Tepals green, anthers yellow. Not rare.
CBL 1306 13 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)