N. Vietnam, prov. Cao Bang, distr. Bao Lac, municipality Yen Lac, vicinities of Yen Lac village (N 22°44′ E 105°50′). Secondary open broadleaved forest on alluvial foothills of remnant karst limestone ridges at 1050-1100 m elev. Cultivated medicinal herb with very long history of cultivation in the area (originated from China ?).
CBL 1359 14 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)