FLORA OF LAOS Nakai-Nam Theun Protected Area Polypodiaceae s.l. (Pteridaceae) Calciphilopteris ludens (Hook.) Yesilyurt & H. Schneid. ( - Doryopteris ludens (Hook.) J. Sm.) Laos, Khammoune prov., Boualapa distr.. Langkhang village, steep southern slopes of sandstone ridge allied to the road from the north betw een points 17°34'02.2"N 105°42'42.6"E, 200 m and 17°34'5L1"N 105°43’01.2"E, 535 m a.s.l. Primary lowland semideciduous and evergreen dry forest on very steep rocky slopes. Terrestrial rhizomatous fern on very steep rocky slopes and cliffs. Locally very common. 15 May 2018, L. Averyanov, Khang Sinh Nguyen, T. Maisak. AL 1090.