N. Vietnam, Thai Nguyen prov., Dong Hy distr., Tan Long municipality, vicinities of Mo Ba village (21°46′21′'N, 105°52′07′'E). Secondary open shrubs along road on limestone at elevation about 150-200 m a.s.l. Woody vine 10-12 m lg in open slope. Flowers: young tepals white with yellowish-pink tint, stamens red-purple, stigma green; tepals of old flowers orange-red-purple. Not rare.