dennstaedtiaceae is one of fifteen families in the order polypodiales, the most derived families within monilophytes (ferns). it comprises 10 genera with ca 240 known species, including one of the world's most abundant fern, "pteridium aquilinum" (bracken). members of the order generally have large, highly divided leaves and have either small, round intramarginal sori with cup-shaped indusia (e.g. "dennstaedtia") or linear marginal sori with a false indusium formed from the reflexed leaf margin (e.g. "pteridium"). the morphological diversity among members of the order has confused past taxonomy, but recent molecular studies have supported the monophyly of the order and the family. the reclassification of dennstaedtiaceae and the rest of the monilophytes was published in 2006, so most of the available literature is not updated.