Vientiane Prov., Kasi Distr., Namken village, Phachao Mt., around point 19°18′45.5”N 102°22′31.4”E.
Primary broad-leaved evergreen forest on very steep rocky slopes of remnant mountain composed with highly eroded solid crystalline limestone at elevations 1500-1750 m.
Lithophytic undershrub 0.5 m tall on mossy rocky mountain top. Flowers reddish. Very common.