USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

Polypodiaceae - The Polypody Family

Perennial ferns from stout, often scaly subterranean stems (rhizomes) or stems with a short, upright, above-ground portion. Leaves commonly referred to as fronds, often large, variously pinnately lobed or dissected, the initial divisions called pinnae, the pinnae themselves sometimes pinnately divided into pinnules; fronds developing from a circinate coil ("fiddlehead"), the petioles well developed, often fairly stout. Fronds all alike, with the fertile frond undifferentiated from the sterile fronds; or the fronds dimorphic, with the fertile fronds specialized and unlike the sterile fronds. Sporangia homosporous, grouped into sori on the undersides of fronds or on the specialized fertile fronds, the sori often covered by a membranous indusium; sporangia small, stalked, dehiscient perpendicular to a vertical annulus; spores released singly, with triradiate ridges. Gametophytes photosynthetic, dorsiventral, terrestrial, monoecious, with sex organs developed on the underside of the prothallium.

A large fern family of which several taxa grow in swampy or boggy places.

Lead Characteristic Go To
1 Fertile fronds brown, structurally unlike the green sterile fronds. Lead 2
1 Fertile and sterile fronds green, structurally similar. Lead 3
2 Sterile fronds pinnate at the base, pinnatifid upward; veins of the pinnae anastomosing. Genus Onoclea (O. sensibilis)
2 Sterile fronds pinnate-pinnatifid; veins of the pinnae free. Genus Matteuccia (M. struthiopteris)
3 Ultimate leaf segments mostly flabellate; sori borne beneath reflexed margins of the lobes on the leaf segments. Genus Adiantum (A. capillus-veneris)
3 Ultimate leaf segments not flabellate; sori borne on the underside of the leaf segments. Lead 4
4 Indusium attached at its center in the middle of the sorus. Lead 5
4 Indusium attached along its margin to one side of the sorus. Genus Athyrium (A. filix-femina)
5 Fronds pubescent, especially on the rachis and midnerves of the pinnae; petioles without scales. Genus Thelypteris (T. palustris)
5 Fronds glabrous; petioles with membranous scales. Genus Dryopteris

4. Polypodiaceae, the Polypody Family

1. Adiantum L. -- Maidenhair fern
1. Adaintum capillus-veneris -- Venus'-hair fern
2. Athyrium Roth
1. Athyrium filix-femina (L.) Roth -- Lady fern
3. Dryopteris Adans. -- Shield fern
1. Dryopteris carthusiana (Vill.) H. P. Fuchs -- Spinulose woodfern
2. Dryopteris cristata (L.) A. Gray -- Crested fern
4. Matteuccia Todaro -- Ostrich fern
1. Matteuccia struthiopteris (L.) Todaro
5. Onoclea L. -- Sensitive fern
1. Onoclea sensibilis L.
6. Thelypteris Schmidel
1. Thelypteris palustris Schott -- Marsh fern

Previous Section -- Ophioglossaceae - The Adder's-tongue Family
Return to Contents
Next Section -- Marsileaceae - The Pepperwort Family

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:37:26 EST
Reston, VA [vaww55]