Polystichum acrostichoides gallery

A common over-wintering fern with dark green leaves

Christmas fern gallery

Emerging fiddleheads

Fiddleheads of Christmas fern start to unfurl in early to mid April. 

Scotia Barrens (Centre Co)
by Maria Pavlova on 04/09/2012
Fiddleheads with last season's fronds

Since this fern is evergreen, you will often find new fiddleheads amongst last year's fronds.

Scotia Barrens (Centre Co)
by Maria Pavlova on 04/12/2012
Unfurling fiddlehead

Fiddleheads are highly scaly and pubescent

Colier Lake (Centre Co)
by Maria Pavlova on 04/23/2010
Emerging fronds

The young fern has distinctive Christmas fern shape

Spring Creek Canyon (Centre Co)
by Maria Pavlova on 04/30/2012
Immature sori
Immature fronds
Growing with cinnamon fern

Christmas fern occasionally grows with other species, such as Osmunda cinnamomea.

Colier Lake (Centre Co)
by Maria Pavlova on 08/20/2011
Fertile and sterile fronds

Fertile fronds have sori on the upper part of the frond and the fertile parts are much narrower than those on the sterile fronds.

Colier Lake (Centre Co)
by Maria Pavlova on 08/20/2011
Autumn fronds

Christmas fern grows in clusters

Scotia Barrens (Centre Co)
by Maria Pavlova on 09/02/2011
In the rain
Centre county
by Maria Pavlova on 09/11/2011
Seedling

First year seedling frond does not grow to full size in one season.

Spring Creek Canyon (Centre Co)
by Maria Pavlova on 11/03/2011
Mid autumn

Typical fern cluster

Colier Lake (Centre Co)
by Maria Pavlova on 09/16/2011
Sori

The fertile portion of the fertile frond, narrowing toward the tip

Colier Lake (Centre Co)
by Maria Pavlova on 11/12/2012
Morphed form

Sometimes the pinnae look highly irregular, with distinctive lobes. 

Colier Lake (Centre Co)
by Maria Pavlova on 11/12/2012
Sori dispersion

Sori can be irregularly dispersed on the pinnae

Colier Lake (Centre Co)
by Maria Pavlova on 11/12/2012
Irregular pinnae
Withering fertile frond

By the end of the growing season, the fertile portion of fertile frond withers away.

Scotia Barrens (Centre Co)
by Maria Pavlova on 01/10/2013
Poking through the snow

Sterile frond in winter

Scotia Barrens (Centre Co)
by Maria Pavlova on 01/10/2013
Aged sori

Because the indusium of this fern dissolves with age, the sori start to look like a brown mass. 

Scotia Barrens (Centre Co)
by Maria Pavlova on 01/13/2013