N. Vietnam, Thanh Hoa prov., Ba Thuoc distr., Co Lung municipality, territory of Pu Luong protected area, near Pu Luong village (20°27′01′'N, 105°11′03′'E). Open secondary dry broad-leaved evergreen forest on very steep slope of remnant highly eroded limestone ridge at elev. 250-500 m a.s.l. Terrestrial herb up to 2 m hg among rocks on steep slope. Flowers unpleasant smelled, external tepals white with greenish tint, central sepal white with light yellow center and reddish-purple pinnate stripes. Common. Flowers unpleasant smelled.