N. Vietnam, prov. Cao Bang, distr. Ha Lang, municipality Thang Loi, vicinities of Lung Sam village (N 22°45′ E 106°42′). Commonest weed up to 0.2 m hg in wet places along rice field at 550 m elev. Flowers dull violet.
CBL 1703 24 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)