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

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

Fiddleheads are highly scaly and pubescent

The young fern has distinctive Christmas fern shape

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

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

Christmas fern grows in clusters

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

Typical fern cluster

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

Sometimes the pinnae look highly irregular, with distinctive lobes. 

Sori can be irregularly dispersed on the pinnae

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

Sterile frond in winter

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