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sensitive fern
sensitive fern (Onoclea sensibilis)
Photo © John Hilty
Features and Behaviors
FEATURES
The sensitive fern has broad, upright fronds that tilt up and backward. The veins can be seen in a network in the fronds. Each frond may be about 24 inches in length. The frond is light green with some hairs on the underside. It is divided into about 12 pairs of leaflets. The leaflet is large and has a wavy margin. Fertile leaves, those producing spores, grow to about 12 inches in length and are upright with small branches. The sensitive fern is also called the “bead fern” for the beadlike fertile spikes it produces. The rachis is light brown or yellow. The stipe is yellow with a brown base and may be longer than the leaf. The fiddleheads are red.
BEHAVIORS
The sensitive fern may be found statewide in Illinois. It grows in moist woodlands, on low open ground and along edges. Spores are produced from June through October. This plant dies back quickly after the first frost.
Illinois Range
Taxonomy
Kingdom: Plantae
Division: Pteridophyta
Class: Polypodiopsida
Order: Polypodiales
Family: Dryopteridaceae
Illinois Status: common, native
