Northern Vietnam, Ha Giang Prov., Quan Ba Distr., Thai An Municipality, in the vicinity of Lo Thang village, around point 22°59′50′'N, 105°05′46′'E. Open grasslands on step alluvial slopes of remnant highly eroded limestone ridge at elev. 1300-1400 m a.s.l. Flowers white. Leaves whitish beneath. Locally common.