Ontario Ferns website

Marsh Fern
Thelypteris palustris

Marsh Fern (Thelypteris palustris) Other common names: Marsh Shield Fern

Other scientific names: Aspidium thelypteris

French names: Thélyptère des marais varieté pubescent

Family: Marsh Fern Family (Thelypteridaceae)

Distinctive features: Leaflet edges curl under; fronds grow singly.

Similar species:
  •   Wood Ferns

  •   Cinnamon Fern (Osmundastrum cinnamomeum) - also grows in wet areas; has tufts at the base of the leaflets; fronds grow from a single point (knob).

  •   Ostrich Fern (Matteuccia struthiopteris) - also grows in moist areas - much taller, stem straight, overall shape is different.

  •   Lady Fern (Athyrium filix-femina) - this is thrice cut and grows in the woods.

Fronds: Twice divided;  Leaflets may curl under at the edges.

Habitat: Wet Areas;  Marshes, wet ground.

Native/Non-native: Native

Status: Common.

Notes: Sometimes mistaken for Cinnamon Fern (Osmundastrum cinnamomeum).

Origin and Meaning of Names:
 Scientific Name: palustris: of swamps, marshes

Photographs: 126 photographs available, of which 12 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Marsh Fern (Thelypteris palustris)

The overall shape of Marsh Fern. Note that the leaflets do not taper much at all towards the base. Note the crooked stem.

Marsh Fern (Thelypteris palustris)

A smaller specimen, upper side.

Marsh Fern (Thelypteris palustris)

Same specimen, underside.

Marsh Fern (Thelypteris palustris)

Closer view of the underside.

Marsh Fern (Thelypteris palustris)

Closeup of the underside - the base of the leaflets lack the tufts that characterise Cinnamon Fern (Osmundastrum cinnamomeum).

Marsh Fern (Thelypteris palustris)

Sometimes it may be found growing in unexpected places, such as this alvar on the Bruce Peninsula. There must be a stable source of moisture at the bottom of this crack in the alvar.

Marsh Fern (Thelypteris palustris)

Closer view of these "out of place" Marsh Ferns.

Marsh Fern (Thelypteris palustris)

And again.

Marsh Fern (Thelypteris palustris)

View of the upper side of the fertile leaflets of Marsh Fern. The leaflet edges curl under quite a bit on the fertile leaflets.

Marsh Fern (Thelypteris palustris)

Underside of fertile leaflets.

Marsh Fern (Thelypteris palustris)

Upper side of a fertile leaflet.

Marsh Fern (Thelypteris palustris)

Underside of the same fertile leaflet.

Range map for Marsh Fern (Thelypteris palustris)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)