N.Vietnam, Bac Kan Prov., Ba Be Distr., Nam Mau Municipality Nam Dai village, Ba Be National Park around point 22025′ 013′'N 1050 35′ 771′'E.
Secondary closed evergreen broad-leaved forest on top of remnant mountains composed with crystalline highly eroded marble-like limestone at elevation 531 m a.s.l. Herb 50 cm hight. Flower deep-violet. On soil, in shady and wet HLF 561 21 Dec. 2002.
Coll. Nguyen Tien Hiep, Jacinto Regalado, Duong Van Xy, Bang Tien Sy Grant from Henry Luce Foundation.