Son La Prov., Van Ho Distr., Xuan Nha Municipality, Muong An village, territory of Xuan Nha natural reserve. Remnants of primary and secondary broad-leaved evergreen dry forest on cliffs and on very steep slopes of remnant hill composed by highly eroded limestone at elevation 900-1000 m a.s.l. around point 20°44’50.1’’N 104°47’54.5’’E. Lithophytic sedge on shady cliffs. Common.