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 250-300 m a.s.l.
Terrestrial herb on open wet sandy places along stream. Flower bracts light pink-violet. Very common.