N.Vietnam, Ha Tinh Prov., Huong Son Distr., Son Hong Municipality, around point 18є34'06''N, 105є11'40''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 250-300 m a.s.l. Canopy epiphyte. Flowers yellow-white. Locally common.