N. Vietnam, Hoa Binh prov., Mai Chau distr., Hang Kia municipality, near Thung Ang village, mountain Tao Xinh (20°43′43′'N, 104°51′21′'E). Primary broad-leaved evergreen dry forest with Calocedrus rupestris (?) on remnant limestone highly eroded ridge at elev 1000-1100 m a.s.l. Shrub 1-1.5 m hg on steep open slope. Common along tops of ridge, tepals yellowish with violet tint, central tepals yellow with deep violet apex.