N.Vietnam, Bac Kan Prov., Ba Be Distr., Nam Mau Municipality, Ba Be National Park around point 22o25′36′'N 105o37′50′'E.
Heavily logged primary evergreen dry broad-leaved forest on very steep slopes and cliffs composed with crystalline highly eroded marble-like limestone along Ba Be lake at elevation 200-250 m a.s.l.
Terrestrial and lithophytic herb up to 0.5 m hg on rocky steep slope. Flowers white, fragrant (at night).
HLF 591 22 Dec. 2002.
Coll. Phan Ke Loc, L.Averyanov, Hoang Van Chat, Do Hoang Chung, Nguyen Manh Hung, Vu Hong Van, Nguyen Tien Vinh, Mai Van Xinh. Grant from Henry Luce Foundation.