Quang Tri Prov., Da Krong Distr., A Vao municipality, Ro Ro village, around point 16°23’06”N 106°57’42”E.
Secondary broadleaved evergreen open forest along rocky river canyon composed with shale and sandstone at elev. about 300 m a.s.l. Treelet 3-4 m tall. Flowers light greenish to almost white. Very common.