Son La Prov., Van Ho Distr., Chieng Xuan Municipality, Co Hong village, territory of Xuan Nha natural reserve, Pha Luong Mountain. Primary coniferous forest with Pinus cernua on very steep mountain slopes and cliffs composed by brown sandstone at elevation 1000-1050 m a.s.l. around point 20°42’14.2’’N 104°43’53.9’’E. Terrestrial sedge on shady steep slope near ridge edge. Common.