N. Vietnam, Prov. Quang Binh, distr. Minh Hoa, 72 km to NWW from Dong Hoi, municipalite Thong Hoa, vicinities of Yen Son village, limestone massif Ke Bang (N 17°40′ E 105°57′). Secondary open shrubs along stream slopes in alluvial valley bottom between limestone ridges and mesas at 200 m alt. Shrub 1-1.5 m hg Flowers brightly purple-violet. Very common. Usual dominante of secondary shrubs on alluvial valley at 200-250 m alt. VH 4702 16.05.1997 International Botanical Expedition of the U.S.A. National Geographic Society (grant No 5803-96)