Lai Chau Prov., Phong Tho Distr., Sin Suoi Ho Municipality, Sa Ma Pho village, around point 22°32′17″N 103°32′41″E.
Secondary open evergreen broad-leaved dry forest and secondary woodlands on very steep mountain slopes composed predominantly with weathered granite at elev. about 1200-1400 m a.s.l.
Erect herb up to 2 m tall in open secondary shrubs. Flowers light blue-violet. Very common, particularly in wet places.
HAL 10795 15 Dec. 2006 Photo. Coll.: Nguyen Tien Hiep, L.Averyanov, Phan Ke Loc, Pham Van The, N.T.Vinh.