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. Flowers yellow. Very common. Commonest weed all over the area.
CBL 1331 14 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)