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. Terrestrial herb to 1.5 m tall in open sandy places along river valley. Flowers yellow. Very common. CPC 2968 9 May 2011