FLORA OF LAOS Carlemanniaceae Silvianthus tonkinensis (Gagnep.) Ridsdale
Vientiane prov., Vang Vieng distr., Patang village, around point 19°04′15.6′'N 102°24′33.2′'E.
Secondary broad-leaved semi-deciduous dry forest on very steep rocky mountain slopes composed by solid marble like highly eroded limestone at elev. about 670 m a.s.l.
Undershrub to 1.5 m tall in shady place. Flowers yellow. Common.