Polystichum acrostichoides, or Christmas fern, is one of the most common ferns in eastern North America, being found in moist and shady habitats in woodlands, stream banks and rocky slopes. The common name derives from the evergreen fronds, which are often still green at Christmas. Christmas fern has a tufted, clumping habit, with its fronds arising from a central growth point. It can form colonies, but frequently grows singly or in twos or threes.