Dryopteris intermedia

Dryopteris intermedia (Muhl. ex Willd.) A. Gray, the intermediate wood fern, is an evergreen eastern North American species also occasionally found in Europe. It is a diploid species, and is the parent of several species of hybrid origin, including Dryopteris carthusiana.

This fern is often confused with several other wood fern species, including D. carthusiana, D. campyloptera, and D. expansa. It especially extensively shares the range of D. carthusiana, but the two may be distinguished by the innermost pinnule on the bottom side of the bottom pinna: this pinnule is longer than the adjacent pinnules in D. carthusiana, but shorter or even in D. intermedia.