Connecticut Plants
Marsh Fern
Thelypteris palustris Schott

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
Thelypteris palustris Schott

Marsh fern growing in a cranberry bog. Only sterile fronds are present.

Thelypteris palustris Schott

Leaflets of a fertile frond, showing the slightly rolled leaf edges. Sterile frond edges are not rolled.

Thelypteris palustris Schott

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.