Online Virtual Flora of Wisconsin

Osmunda claytoniana L.

Family: Osmundaceae

interrupted fern

Emmet J. Judziewicz

Christopher Noll

University of Wisconsin - Madison (WIS-VP)

Open Interactive Map

Etymology: Osmunda: Osmunder for "Thor" a Saxon name for a Celtic god
Plants: perennial fern
Conservation Status: Native

Common in mesic to wet wooded areas, edges of bogs and cedar swamps, ditches, and shrub thickets. It tends to grow on higher ground and in better drained soil than cinnamon fern. Fertile leaves, arising in mid-May, are entirely green as they unfurl, with the 2--5 smaller fertile pinnae in the middle turning dark brown. Sterile leaves on the outside of the clump spread outward and lose the hairs on the rachis, retaining only a few scattered hairs. Lobes of the pinnae are rounded, without a sharp tip.