Northern Vietnam, Ninh Binh Prov., Nho Quan Distr., Cuc Phuong Municipality, Cuc Phuong National Park, about 0.5 km W from Bong locality, 20°21′01′'N, 105°35′38′'E. Primary closed evergreen seasonal broad-leaved lowland forest on steep rocky slopes of limestone hills at elev. about 400-450 m a.s.l. Lithophytic creeping herb on mossy rock outcrops on tops of hills. Leaves uniform light green. Rare.