The dark green fronds of this fern grow to 50-180 cm tall, in a tight clump spreading out radially from a round base. They are single-pinnate, with the pinnae alternating on the stalk. Each pinna is 1-15 cm long, with a small upward-pointing lobe at the base, and the edges are serrated with bristly tips. It has an underground rootstock called a rhizome, which anchors the plant into the substrate, where, by means of small, hairlike roots, minerals and water are drawn from the soil.

Western Sword Fern is an evergreen fern native to western N. America, where it is one of the most abundant ferns occurring along the Pacific coast from southeast Alaska south to southern California, and also inland east to southeastern British Columbia, northern Idaho and Montana, the Black Hills in South Dakota, and on Guadalupe Island off Baja California.