Quang Binh Prov., Minh Hoa Distr., Dan Hoa Municipality, Bai Dinh village around point 17°44′04”N 105°49′14”E.
Remnants of primary evergreen broad-leaved forest on very steep slopes and on tops of remnant hills composed with highly eroded marble-like solid limestone at elevation about 400-500 m a.s.l.
Semi-woody vine to 15 m long in shrubs on rocky hill top. Flowers light violet. Locally very common.
HAL 12476 8 February 2009 Coll.: L.Averyanov, P.K.Loc, N.T.Vinh, L.T.Son.