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DescriptionA specimen of this native perennial fern consists of a much-branched bipinnate leaf and its petiole. This compound leaf is 6-24" across and nearly as long; it is reniform (kidney-shaped) or fan-shaped in outline, and held more or less horizontal to the ground. The petiole is 6-18" tall; it is black or dark brown, wiry, and erect. The petiole divides into two major branches that widely diverge from each other. Along one side of each branch, there are several straight leafy stalks (pinnae) that are odd-pinnate. Each leafy stalk (rachis) is up to 12" long and 2" across; it has 4-24 pairs of leaflets along its length and a single terminal leaflet. These leaflets are arranged alternately along the stalk on short petiolules; they are medium green. The non-terminal leaflets are up to ½" long and 1" across; they are plume-shaped. One side of the non-terminal leaflet is smooth and slightly curved, while the other side is shallowly cleft and crenate-dentate. The larger lobes of each leaflet have rounded or truncate tips. The terminal leaflets are up to ¾" long and ¾" across; they are fan-shaped. The lower two sides of the terminal leaflet are smooth and straight, while the upper side is shallowly cleft and crenate-dentate. The sporangia (spore-bearing structures) are located near the lobed tips of the leaflets. Each of these leaflet tips folds downward and partially covers its sporangia; these small sporangia are arranged together in a narrow band. The spores are produced and released during the summer or fall. The root system is fibrous and rhizomatous. Small colonies of plants are often produced from the long slender rhizomes.