Vientiane Prov., Vang Vieng Distr., Na Khun Village, around point 18°52′28”N 102°24′21”E.
Remnants of primary evergreen broadleaved forest on flat alluvial valley at the base of high remnant hills composed with solid marble-like highly eroded rocky limestone at elevation around 300 m a.s.l.
Terrestrial fern with fronds to 1 m tall in rather open wet grassy place along stream. Very common.