Dennstaedtiaceae

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 ferns, 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.

==Distribution of genera== Generally, the family is pantropical, but due to the distribution of Pteridium (the most widespread fern genus), Dennstaedtiaceae can be found worldwide. Pteridium is a well adapted early successional genus, generally described as a weed because of its ease of spread. The spore is light and robust, so it can travel relatively far and colonise open, disturbed environments easily. Dennstaedtia is mostly tropical to warm-temperate, but not well represented in the Amazon or Africa. Oenotrichia is in New Caledonia. Leptolepia is in New Zealand, Queensland (Australia), and in New Guinea. Microlepia is in the Asiatic-Pacific. Paesia occurs in tropical America, Asia, and the western Pacific. Hypolepis is tropical and south-temperate. Blotiella is strongly centered in Africa. Histiopteris is generally Malesian, with one pantropic to south-temperate species. The extinct genus Krameropteris is known from remains found in Cenomanian aged Burmese amber. Some older fossils are known from the Jurassic of Eastern India .