N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Dong Loan, vicinities of Ban Lung and Lung Phuc (N 22°46′ E 106°44′), about 50 km to E from Cao Bang town. Secondary evergreen forest on alluvial walley among limestone rocks on foothills of remnant limestone ridges at 400 m alt. Herb up to 2 m hg in secondary shrubs along streamlet. Not rare. Common weed.
CBL 585 24 Nov. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)