Marsh Fern, Thelypteris palustris
A medium-sized, delicate looking fern that can grow in a variety of habitats, this species can easily be confused with Hay-scented or Lady Fern. However, the stipe (stem) is dark brown with very few scales (unlike Lady), or hairs (unlike Hay-scented).
As of 2007 we have found only one specimen of Marsh Fern at Fresh Pond Reservation, in the woods between Little Fresh Pond and the golf course clubhouse.