Tags: Fern.
Dennstaedtiales is an order of ferns that includes 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).
