Cao Bang Prov., Bao Lam Distr., Yen Tho municipality, Cha Hai village, Phia Hai Mt. Secondary highly degraded broad-leaved evergreen forest on steep mountain slopes near mountain top at elevation 1300-1350 m a.s.l. around point 22°41’22.3’’N 105°34’43.5’’E. Lithophytic sedge on vertical cliffs composed by shaly stratified limestone. Locally common.