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.
Terrestrial and lithophytic herb on rocky mountain top at elev. 1000 m. Flowers white. Very common.
LA-VN 838 24 March 2013 Coll.: L.Averyanov, N.S.Khang, S.Lorphengsy