N. Vietnam, prov. Cao Bang, distr. Nguyen Binh, municipality Ca Thanh, vicinities of Ta Phinh village (N 22°44′ E 105°50′). Secondary short tall grasslands on alluvial valley between limestone ridges at 1100-1150 m alt. Flowers whitish. Common. CBL 1582 19 April 1999
International Botanical Expedition of the U.S.A. National Geographic Society (grant No 6300-98)