This is a very common fern in wet, sunny areas.
- Synonyms: Dryopteris thelypteris, Thelypteris thelypteroides
- Family: marsh fern (Thelypteridaceae)
- Habitat: edges of marshes and wet meadows, ditches, or woods; usually in rich, wet soil but not in standing water
- Height: 18-24 inches
- Location of spores: Underside of fronds, on rows of dots near the midvein. Fertile fronds have leaf edges that are slightly rolled over the spore-bearing sori (see photos below).
- Petiole (leaf stalk): smooth and pale green above, black at base
- Growth pattern: random
- Persistence: deciduous
- Origin: native
Marsh fern growing in a cranberry bog. Only sterile fronds are present.
Leaflets of a fertile frond, showing the slightly rolled leaf edges. Sterile frond edges are not rolled.
Underside of a fertile leaflet, showing the leaf edges curled around the sori (spore-bearing dots). These rolled edges distinguish marsh fern from its relative Massachusetts fern.