N. Vietnam, prov. Cao Bang, distr. Tra Linh, municipality Luu Ngoc, vicinities of Lung Mu village (N 22°47′ E 106°18′), about 14 km from Cao Bang town to the N. Secondary shrubs and grasslands on alluvial valley between remnant limestone ridges and mesas at 600-650 m alt. Herb 0.5-1.2 m hg in open places. Common weed in the area.
CBL 1152 13 Dec. 1998
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)