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. Primary coniferous forest with Tsuga chinensis on remnant highly eroded limestone ridge at elev. about 1600 m a.s.l. Tree 20-25 m hg. Associate of first forest stratum. Stomata banks whitish. Occasional.