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fragile fern

fragile fern (Cystopteris protrusa) Photo © John Hilty

Features and Behaviors

The fragile fern is a small, green fern. Each of its fronds is about 10 inches long and three inches wide with approximately 12 pairs of leaflets. The stipe may be upright or along the ground. The stipe is shorter than the length of the frond and is easily broken near its base. Because of this trait the fragile fern is also known as the brittle fern. The stipe is yellow‐brown or green toward the frond, shading to dark brown or black near the base.

The fragile fern may be found statewide in Illinois. It grows in upland forest along ledges and around rocks. Spore production occurs from June through September. The fragile fern often grows in early spring and early fall, dying back in summer.

Illinois Range


​Kingdom: Plantae
Division: Pteridophyta
Class: Polypodiopsida
Order: Polypodiales
Family: Dryopteridaceae

Illinois Status: common, native