Pteridium

…100 metres [330 feet], in Pteridium), hairy; leaves 2 to 4 times pinnately compound, glabrous or hairy; sori mostly marginal or submarginal, discrete or in a more or less uninterrupted line, the indusium cup-shaped or lateral and elongate, sometimes also with the segment margin reflexed; sporangia with the annulus vertical;…

…12,000 species; representative genera include Pteridium, Polypodium, Polystichum, Adiantum, and Cyathea. Class Equisetopsida (horsetails, scouring rushes) Vascular plants; sporophyte

…important genus of Dennstaedtiaceae is Pteridium. Bracken (P. aquilinum) is considered one of the world’s worst weeds and is an aggressive invasive species in some areas outside of its native range. Bracken invades open or disturbed areas with its extensive branched rhizomes, which may grow to about 400 metres (1,300…