S Vietnam, Quang Tri Prov., Huong Hoa Distr., Huong Phung municipality, Sa Mu pass on Ho Chi Minh trail at elev. of 1130 m a.s.l. around the point 16°48'17 N, 106°34'28 E. Wet evergreen broadleaved forest on very steep montane slopes composed of granite and sandstones.