Son La Prov., Yen Chau Distr., Muong Lum Municipality, Na Vang village around point 21°01′19”N 104°30′45”E.
Primary coniferous mixed forest with Calocedrus rupestris on very steep rocky slopes of remnant mountain composed with highly eroded solid limestone at elevation 900-1100 m a.s.l.
Lithophytic scandent shrub to 2 m tall on open mossy rocky outcrops on the top of mountain. Flowers white. Not common.
CPC 1906 2 April 2011 Photos. Coll.: L.Averyanov, N.T.Hiep, T.B.Ngan.