N. Vietnam, prov. Cao Bang, distr. Bao Lac, municipality Yen Lac, vicinities of Yen Lac village (N 22°44′ E 105°50′). Secondary wet short tall grasslands on alluvial shale valley between limestone remnant karst ridges at 1000-1050 m elev. Prostrate creeping herb in wet places. Flowers white. Very common. Commonest weed in the area.
CBL 1340 14 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)