2. Pteridium Gled. ex Scop. (bracken)

(Tryon, 1941)

One species, nearly worldwide.

Although traditionally thought to comprise a single species consisting of a dozen varieties grouped into two subspecies, several recent authors have recognized two to several species. The interrelationships among the various taxa require further study before the question of species limits in Pteridium can be resolved. Until these can be elucidated, the two taxa present in Missouri are retained as varieties of P. aquilinum.