This volume provides a wealth of information on the filmy fern family (Hymenophyllaceae) in Malesia, the tropical region extending from Peninsular Malaysia to New Guinea. Eight genera and 104 species including all 17 species native to Singapore are included, and detailed descriptions, synonymy, and identification keys, as well as information on distributions, habitats and ecology, fossils, reproduction and phytochemistry are provided. Morphological characters and Hymenophyllaceae systematics and molecular phylogenetics are discussed.