N.Vietnam, Ha Tinh Prov., Huong Son Distr., Son Hong Municipality, around point 18°34′06′'N, 105°11′40′'E. Primary broad-leaved evergreen riparian forest with Platanus kerrii and Duabanga grandiflora along rocky Song Con river valley composed with shale and gray sandstone at elevation about 250 m a.s.l.
Woody vine 15-20 m long. Flowers white. Not common.