Distribution
United States of America

Native to: Alabama, Arkansas, China North-Central, China Southeast, Chita, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Illinois, Indiana, Inner Mongolia, Iowa, Japan, Kansas, Kentucky, Korea, Kuril Is., Labrador, Louisiana, Maine, Manchuria, Manitoba, Maryland, Masachusettes, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Brunswick, New Hampshire, New Jersey, New York, Newfoundland, North Carolina, North Dakota, Nova Scotia, Ohio, Oklahoma, Ontario, Pennsylvania, Prince Edward I., Québec, Rhode I., Sakhalin, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin, Wyoming.
Introduced into: Baltic States, Belgium, Great Britain, Netherlands, North European Russi.

Leaves irregularly spaced along stem. Sterile leaves yellow-green, deltate, coarsely divided, 13-34 × 15-30 cm. Petiole of sterile leaf black, 22-58 cm, flattened at base; rachis winged, becoming broader toward apex. Pinnae 5-11 per side, lanceolate; proximal pinnae 9-18 cm, margins entire, sinuate, or laciniate. Sporophyll leaves green, becoming black at maturity, oblong, 7-17 × 1-4 cm. Petiole 19-40 cm, base sparsely scaly. Pinnae linear, 5-11 per side, 2.5-5 cm; ultimate segments revolute to form beadlike structures, 2-4 mm diam. Sori borne on free veins, enclosed by ultimate segments. 2 n = 74.
Sporophylls produced May-October. Open swamps, thickets, marshes, or low woods, in sunny or shaded locations, often forming thick stands; 0-1500 m.