N. Vietnam, prov. Ha Giang, distr. Dong Van, municipality Ho Quang Phin, vicinities of Ta Xa village, 14-16 km to SSW of Dong Van town (N 23°16′ E 105°22′). Open secondary shrubs among limestone rocks on alluvial limestone ridge foothills at 1300 m alt. Prostrate terrestrial and lithophyte herb in wet open places. Flowers white. Very common. Commonest weed in the area.
CBL 1716 28 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)