Perennial fern 30 cm - 1.2 m tall Leaves: clustered, stalked, green, narrow, twice pinnately compound, typically hairless on upper surface, but glandular on lower side of main "midrib" (rachis), which also has lengthwise groove on upper surface. Rhizome: short-creeping to erect, scaly. Spores: misshapen, sterile.
Similar species: Dryopteris x dowellii is most similar to its two parent species, D. intermedia and D. clintoniana. Its distinguishing characteristics are that it has twice pinnately compound leaves with glandular hairs on the rachis, pinnae "midribs" (costae) and flaps of tissue over the spore clusters (indusia) as in D. intermedia, but has narrow leaf blades with the lowest leaf divisions (pinnae) being triangular. It also only produces sterile, misshapen spores.
Habitat and ecology: Very rare, only reported in Porter County, Indiana in a swamp.
Occurence in the Chicago region: native
Etymology: Dryopteris is from the Greek drys (oak), and pteris (fern) referring to the plant's habitat. Dowellii is named after a botanist with the surname Dowell.