Marsh Fern
Marsh fern, Thelypteris palustris, is found in many places in the Northern Hemisphere, especially along the Appalachian Mountains and Great Lakes of the USA.
iNaturalist.org map of T. palustris
T. palustris is similar to two other species, T. simulata and Amauropelta noveboracenis. In fact, T. palustris and T. simulata were thought to be the same species
T. palustris Blade tapers gradually forming a triangle.
T. simulata has a long, smooth stipe. Fertile pinna curl over the sori. Blade is wide in the middle and tapers quickly.
A. noveboracenis has pinna all the way down to the ground, thus has a very short stipe.
T. simulata has a slightly scaly stipe. Fertile pinna are not changed with sori present.
Stuart McKinney Wildlife Refuge, Stratford, CT, USA
Stuart McKinney Wildlife Refuge, Stratford, CT, USA
Stuart McKinney Wildlife Refuge, Stratford, CT, USA
The pinna curl over the sori, a specie character.
Stuart McKinney Wildlife Refuge, Stratford, CT, USA
Stuart McKinney Wildlife Refuge, Stratford, CT, USA