Northern Vietnam, Ha Giang Prov., Quan Ba Distr., Thanh Van Municipality, in the vicinity of Lung Cung village, around 1 km to the E from point 23°05′32′'N, 105°00′10′'E. Primary coniferous forest with Pseudotsuga brevifolia on remnant highly eroded limestone ridge at elev. 900-1000 m a.s.l. Woody vine about 20 m lg. Rare.