Northern Vietnam, Ninh Binh Prov., Nho Quan Distr., Cuc Phuong Municipality, Cuc Phuong National Park, Dang locality, about 1 km WNW of Dang Forest Control point, 20°16′28′'N, 105°40′57′'. Secondary closed evergreen seasonal broad-leaved lowland forest on limestone hills at elev. about 400 m a.s.l. Lithophytic herb on vertical shady cliffs. Very common on tops of hills.