FLORA OF VIETNAM Carlemoniaceae Silvianthus tonkinensis (Gagnep.) Ridsdale
Son La Prov., Van Ho Distr., Tan Xuan comm., A Lay village, around point 20°40′46.2N 104°39′49.6E.
Primary evergreen broad-leaved forest on very steep rocky slopes and on mountain tops composed with red-brown sandstone at elevation about 1500 m a.s.l.
Shrub or treelet 3-4 m tall on on steep shady slope. Flowers and fruits white to light pibkish-violet. Common, particularly along rocky strems.