Tuyen Quang Prov., Na Hang Distr., Sinh Long Municipality, Nam Duong Vill., Xo Lo Tre Valley, around point 22°35′40″ N, 105°21′05″ E, 495 m In logged closed primary evergreen broad-leaved lowland forests on slopes of sand- and shalestone mts. Evergreen trees, ca. 15 x 0.25 m; flower bud covered densely by rusty hairs; fallen down fruits, destroyed by wet climate