Vientiane prov., Kasi distr., between San and Tham Tai villages, around point 19°17′47.9′'N 102°08′58.9′'E.
Secondary broad-leaved evergreen dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. 900-1000 m a.s.l.
Terrestrial herb to 2 m tall on rather open rocky slope. Flowers violet. Common.