Quang Binh Prov., Minh Hoa Distr., Dan Hoa Municipality, Bai Dinh village around point 17°45′28”N 105°46′14”E.
Remnants of primary evergreen broad-leaved forest on very steep slopes and on tops of low remnant hills composed with highly eroded marble-like solid limestone at elevation about 200-300 m a.s.l.
Lithophytic herb to 1 m tall on open rocks on rocky top of hill. Flowers blue-violet. Common.
HAL 12361 7 February 2009 Coll.: L.Averyanov, P.K.Loc, N.T.Vinh, L.T.Son.