Son La Prov., Van Ho Distr., Xuan Nha Municipality, Muong An village, territory of Xuan Nha natural reserve.
Remnants of primary and secondary broad-leaved evergreen dry forest on cliffs and on very steep slopes of remnant hill composed by highly eroded limestone at elevation 900-1000 m a.s.l. around point 20°44′50.1″N 104°47′54.5″E.
Semi-woody vine 4-6 m long among open secondary shrubs along trail. Flowers reddish. Occasional.