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 355 m a.s.l.
Lowland closed secondary old evergreen forest on steep slopes along rocky stream valley composed with stratified solid shale and sandstone.
Herbaceous vine 2-3 m long on mossy rocks on steep shady rocky stream slope. Flowers yellow. Common.
HLF 6833 20 March 2007.
Coll. Averyanov L., P.K.Loc, N.V.Trai, N.T.Vinh, N.D.Phuong, Averyanova A. Grant from Henry Luce Foundation.