fern of the genus Pteridium, represented by a single species (P. aquilinum). Twelve varieties are found throughout the world in temperate and tropical regions. It is a noxious weed, with a perennial black rootstock that creeps extensively underground. At intervals along the rootstock, the plant sends up fronds that may reach a height of 15 ft (5 m) or more. Though they die in autumn, the fronds often remain standing throughout winter, affording cover for wildlife in some areas. The fronds are used for thatching and as fodder.