Christmas Fern
Christmas fern, Polystichum arcostichoides, is found in many places in the Eastern United States, and not many places elsewhere in the world.
iNaturlist.org map of Christmas Fern
P. acrostichoides is a low to the ground fern. It grows in clumps. It is an evergreen fern. It has been used for Christmas decorations, thus its name.
The pinna have a distinct shape that has been referred to as a boot, Santa's sleigh, and other such shapes.
The frond can be completely sterile or the lower half is sterile and upper half is fertile.
A hillside of P. acrostichoides Aspetuck Land Trust, Weston, CT, USA
Fertile pinna of upper half of P. acrostichoides frond. Fairfield, CT, USA
Fertile pinna on upper half of fertile frond, Kent Land Trust, Kent, CT, USA
Sterile frond, somewhat immature, Kent Land Trust, Kent, CT, USA
Broken pinna upside down with sori covered in morning frost