N.Vietnam, Bac Kan Prov., Ba Be Distr., Nam Mau Municipality: mountaine betwen Khau Cum to Nam Dai. Ba Be National Park around point 22(26′311N 105(36′ 669 E.
Selectly logged primary evergreen closed broad-leaved forest on top mountain composed with crystalline highly eroded marble-like limestone at elevation 386 m a.s.l.
Climbring herb Epiphyte on tree in shady and open place, white latex succulence.Common HLF 646 25 Dec. 2002.
Coll.Nguyen Tien Hiep, Do Hoang Chung, Vu Hong Van. Grant from Henry Luce Foundation.