Phylogenetic Systematics of the Polypodiaceae (Filicales)

In his introductory statements to 'The Symposium on the Phylogeny and Classification of the Filicopsida' which was held in London, 1972, HOLTTUM, when dealing with 'dubious groups of relationships which would particularly repay investigation', mentioned the Polypodiaceae first (HOLTTUM, 1973: 6). Talking about Polypodiaceae the present authors deal with the Polypodiaceae sensu stricto only, thus excluding the Cheiropleuriaceae, Dipteridaceae, Grammitidaceae, and also the Loxogrammaceae, taxa which were formerly (or are still) included in the Polypodiaceae sensu lato. As delineated in this way, this almost exclusively pantropical family consists of about 600 species and an indefinite number of genera.