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Northern Prairie Wildlife Research Center

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Aquatic and Wetland Vascular Plants of the Northern Great Plains

4. Polypodiaceae, the Polypody Family

4. Matteuccia Todaro -- Ostrich fern

1. Matteuccia struthiopteris (L.) Todaro

Rhizomes stout, branching and scaly, giving rise to short upright stems which bear the fronds. Fronds annual (in the northern plains), dimorphic, the fertile frond stiffly erect in the center of a circle of sterile fronds, blackish to brown, structurally unlike the green sterile fronds. Sterile fronds ascending, pinnate-pinnatifid, to 17 dm tall; blades much longer than the petioles, mostly 15-35 cm wide, sparsely to obviously pubescent on the rachis, abruptly narrowed to the tip, gradually tapered to the base; pinnae 20 to many pairs, ascending, mostly alternate, 7-22 cm wide, deeply divided into 20 or more pairs of pinnules, these 3-6 mm wide at the base; veins pinnate, free, not anastomosing. Fertile frond shorter than the sterile ones, to 5 dm tall; blade pinnate-pinnatifid, 12-25 cm long; pinnae ascending to appressed, 2-6 cm long, the margins revolute to enclose the sori, eventually spreading and the pinnules separating to expose the sporangia; sori several on each pinnule, the pinnules 1-2 mm wide; indusium hyaline, hoodlike, lacerate. Fertile fronds produced Jun--Jul, often persistent into the following year. Wet or swampy woods and stream margins; occasional; e and c ND, ne SD and the Black Hills; (Newf. to AK, s to VA, OH, MO, SD and B.C.; also in Europe). Pteretis pensylvanica (Willd.) Fern.

The ostrich fern is commonly planted as an ornamental in shaded places around homes. It spreads readily by rhizomes.

GIF- Distribution Map

Map key

Previous Species -- Dryopteris cristata (L.) A. Gray -- Crested fern
Return to Family -- Polypodiaceae - The Polypody Family
Next Species -- Onoclea sensibilis L.

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