POLYPODIACEAE (Polypody Family)

About 40 genera, about 500 species, worldwide.

Many previous authors have treated the Polypodiaceae in a far more inclusive sense than has been accepted in the present volume. Research by several authors on the relationships among the ferns has resulted in the dissection of the family into a number of distantly related families (the number of segregates to be recognized remains controversial). The present classification follows that of the Flora of North America (Flora of North America Editorial Committee, 1993), and several genera formerly included in the Polypodiaceae are herein referred to the Aspleniaceae, Blechnaceae, Dennstaedtiaceae, Dryopteridaceae, Pteridaceae, and Thelypteridaceae.