FLORA OF LAOS Polypodiaceae s.l. Onychium sp.? (or Pteris sp.?)
Houphan Prov., Viengxay Distr., Xieng Luong village, around point 20°22′06.1′'N 104°17′18.6′'E.
Primary and secondary broad-leaved evergreen dry forest on very steep rocky slopes of highly eroded mountains composed by solid marble-like limestone at elev. 600-700 m a.s.l.
Lithophytic fern in mossy crevices of shady vertical cliff on mountain top. Not common.