Kingdom: Plantae
Division: Pteridophyta (Filicophyta)
Class: Pteridopsida (Filicopsida)
Subclass: Polypoditae
Order: Dryopteridales
Family: Dryopteridaceae
Genus: Polystichum

Polystichum acrostichoides

Common name: Christmas fern

• Polystichum acrostichoides
• Range: Eastern North America
• Chromosome count: based on n=41
• Confused with: Athyrium pycnocarpon, narrow glade fern

The Christmas fern is so-called because it is evergreen and has been used in the past for Christmas decoration. It is one of our most common and widespread ferns, growing in a wide variety of situations. However, its preferred environments are the lower parts of wooded hillsides and stream banks in the woods. The fronds are dimorphic. The smaller fronds are sterile, and the larger fronds are sterile on the lower two-thirds, but the third or so of the distal pinnae are highly constricted, bearing dense sori on the backs.

The Christmas fern can be an effective erosion control. The fronds begin the year erect, but slowly decline into fall then become recumbent on the ground after a hard frost. They then persist for another year or two after dying, holding in place leaves and other duff.

The Christmas fern is very easy to grow and is attractive in many situations, with dark green, shiny leaves. It grows from a crown and over a period of years will make a very large, dense clump. The fronds may also be used in flower arrangements.