This classification differs radically from the old traditional scheme, in which most ferns were included in the Polypodiaceae. This is somewhat of a "splitter" classification, in order that it may as much as possible reflect recent cladistic research into the true relationships between the plants. Technically, all gymnosperms and flowering plants also should fall within the phylum Pterophyta (Filicophyta) in order to indicate the correct relationship. This is provisionally my own scheme, drawn from several different sources, although leaning heavily on the recent cladistic publication of the American Fern Society.