Tuyen Quang Prov., Na Hang Distr., Sinh Long Municipality, Khuoi Phin village, around point 22°38′21.9″N, 105°20′43.5″E. Primary evergreen mixed humid forest on rocky limestone on highly eroded karstic hills composed with gray solid marble-like limestone at elevation 1100-1200 m a.s.l. Semiwoody creeping epiphytic and lithophytic vine 4-5 m long. Not rare. 29 September 2013 CPC 5291 / TM 1018 - living plant. L.Averyanov, N.T.Hiep, L.M.Tuan, N.S.Khang, D.V.Cuong, N.V.Truong.T.Maisak, L.Osinovets
Flowered in 3 July 2017. Flowers white with quite distinct sweet, rather unpleasant fragrance. Photos. L. Averyanov.