Ha Giang Prov., Bac Me Distr., Phieng Luong municipality, around Phieng Luong village.
Primary broad-leaved humid evergreen forest on very steep slopes and along rocky ridge composed with solid crystalline highly eroded limestone at elevation 1100-1150 m a.s.l. around point 22°38′07.1″N 105°19′22.1″E.
Lithophytic herb to 1 m tall on mossy shelves of shady vertical cliff near mountain top. Flowers white, anthers dull purple-violet. Rare.