Dryopteris x boottii (Tuck.) Underw. (pro sp.) [cristata × intermedia]
Family: Dryopteridaceae
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Perennial fern 30 - 80 cm 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 somewhat erect, scaly.

Spores: misshapen, sterile.

Similar species: Dryopteris x boottii is most similar to its two parent species, D. intermedia and D. cristata. The distinguishing characteristics of the hybrid are that it has twice pinnately compound leaves with glandular hairs on the rachis and pinnae "midribs" (costae) and flaps of tissue over the spore clusters (indusia) as in D. intermedia, but narrow leaf blades with the lowest leaf divisions (pinnae) being triangular and usually shorter than those above, as in D. cristata. It also only produces sterile, misshapen spores.

Habitat and ecology: Observed occasionally in wetter woods in our eastern counties.

Occurence in the Chicago region: native

Notes: This is a sterile hybrid between Dryopteris intermedia and D. cristata.

Etymology: Dryopteris is from the Greek drys (oak), and pteris (fern) referring to the plant's habitat. Boottii is named after one of several botanists from the 1800's with the surname Boott.

Author: The Field Museum