Vietnam, Nghe An Prov., Tuong Duong Distr., Tam Quang Municipality, Tung Huong village, along Khe Mat stream around point 19°03′09″N 104°36′53″E at elevation about 300-350 m a.s.l.
Lowland closed secondary evergreen forest on steep slopes along rocky stream valley composed with stratified solid shale and sandstone.
Herbaceous vine 4-6 m long in open shrubs on river bluffs. Flowers whitish. Very common.
HLF 6890 21 March 2007.
Coll. Averyanov L., P.K.Loc, N.V.Trai, N.T.Vinh, N.D.Phuong, Averyanova A. Grant from Henry Luce Foundation.