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This perennial fern consists of a loose rosette of sterile leaves about 2-4' tall; these leaves are ascending to nearly erect. In the middle of this rosette, fertile leaves are produced during the spring or summer; they are erect and somewhat shorter than the fertile leaves. The sterile leaves are pinnate-pinnatifid in structure and oblong-lanceolate to lanceolate-ovate in outline; they have 12-25 pairs of leaflets along their rachises (or central stalks). The leaflets are pinnatifid and narrowly lanceolate in outline; they have 10-20 pairs of lobes, tapering gradually into narrow tips. At the bases of leaflet undersides (at the junction of their stalks with the rachis of the leaf), there are persistent tufts of woolly brown hairs. Leaflet lobes are broadly oblong in shape and smooth along their margins; these margins are initially ciliate, but they soon become eciliate (hairless). The tips of these lobes are more or less well-rounded. Venation of individual lobes is pinnate, consisting of a straight central vein and several forked lateral veins. The leaflets of sterile leaves are light to medium green or yellowish green; these leaflets are initially pubescent, although they soon become glabrous. The rachises and petioles of sterile leaves are light green, yellowish green, or silvery white; these rachises and petioles are more or less covered with brown woolly hairs, especially while they are young. The rachises and petioles are flat along their upper sides and strongly convex along their lower sides. The petioles are about one-fourth of the length of the leaves. The fertile leaves have the same pinnate-pinnatifid structure as the sterile leaves, but their contracted leaflets are held erect and they are covered with reddish brown sporangia and reddish brown woolly hairs. These small sporangia are globoid in shape and split open to release their spores during the summer. These tiny spores are distributed by the wind. The root system consists of a crown of fibrous roots, from which spreading rhizomes are occasionally produced. Cultivation


Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© John Hilty

Source: Illinois Wildflowers


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