Christmas Fern

Media
Photo of Christmas fern leaves lying against fallen oak leaves
Scientific Name
Polystichum acrostichoides
Family
Dryopteridaceae (wood-ferns)
Description

Christmas fern is a perennial fern that bears two types of leaves (fronds). Leaves that produce spores have the spore-producing leaflets (pinnae) at the upper third of the frond; these fertile leaflets are notably smaller and thinner than the vegetative (non-spore-producing) leaflets on the basal portion of the frond. The fertile leaves usually stand more upright than the sterile leaves, and their smaller, spore-bearing leaflets usually wither by winter. The sterile leaves, lacking spore-producing pinnae, have a more regular appearance and are evergreen, lasting through the winter, often lying flat on the ground. The leaf stalks are green and have scales (they are not shiny). In spring, the fiddleheads (developing fronds) are scaled and silvery.

Looking more closely at the leathery, rich green leaves, the lance-shaped leaflets are spiny-toothed with bristle tips, looking something like holly leaves. Leaflets usually have an earlike lobe at the base of the upper side. The spore clusters are in rows of circular, umbrella-like structures, which can be so close together that they may cover nearly the entire leaflet undersurface. Spores are produced June–October.

Common Name Synonyms
Holly Fern
Size
Leaves: 4 to 30 inches long; leaflets: usually 2 to 3 inches long.
Where To Find
Statewide.
Occurs on wooded slopes in both dry and moist substrates, usually in shady or somewhat shady areas. One of the most common ferns in Missouri’s forests and woodlands.
Life Cycle
Christmas ferns, like other ferns, have a two-parted life cycle. The plant we usually see is called a sporophyte, because it produces spores. Spores, produced on the undersides of the leaves, are extremely small seedlike packages of genetic material that can blow in the wind or be carried by water. When the spores germinate, they become the other part of the life cycle, the gametophyte. The gametophyte is a tiny, flat, green, heart- or kidney-shaped plant that bears organs that produce eggs and sperm. The sperm must swim to reach the eggs, so liquid water must be present for fertilization to occur. The fertilized eggs then develop into new sporophyte plants — the ferns we are accustomed to seeing.

Pioneers used the holly-like evergreen leaves of this fern to make Christmas wreaths, hence the name.

In cultivation, Christmas fern provides winter interest in woodland, shade, or native plant gardens, along walls, or on slopes. On slopes, it helps to prevent erosion. If you wish to plant Christmas fern, make sure you get your plants from reputable native plant dealers. Don’t dig them from the wild.

Ferns and their relatives dominated the landscape in the Carboniferous Period, about 300 million years ago. Through geologic processes, they, and the carbon they had taken from the air and trapped in their tissues, were transformed into coal. In a way, the coal we burn for energy is a plant resource — fossilized fern forests. When we burn coal, we are taking carbon that had been buried underground for millions of years and releasing it back into the atmosphere.

During winter, the prostrate fronds of Christmas fern hold fallen leaves against the ground, speeding their decomposition and enriching the soil.

Christmas ferns and other plants help to stabilize soils on slopes, preventing erosion.

Not many animals eat the leaves of Christmas fern.

Like other evergreen plants, Christmas fern can conduct photosynthesis on warm winter days. Also, it can take advantage of sunny days in early spring and late fall, when leafless trees permit sunshine to reach the forest floor.

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About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!