(Bracken or Common Bracken) is a species of fern with occurring in temperate and subtropical regions throughout much of the northern hemisphere.
It was traditionally treated as the sole species in the genus Pteridium (brackens), however authorities have splt and recognised up to 11 species in the genus.
It is a herbaceous perennial plant, deciduous in winter. The large roughly triangular fronds are produced singly, arising upwards from an underground rhizome, and grow to 1-3 m (3-10 ft) tall; the main stem, or stipe, is up to 1 cm (0.4 in) diameter at the base.
An adaptable plant, it readily colonises disturbed areas. It can even be invasive in countries it is native, such as England, where it has invaded heather (Calluna vulgaris) stands on the North Yorkshire moors.