Ferns and Fern Allies: Differences and Examples Within Prairie Ferns and Horsetails

What Is the Difference Between a Fern and a Fern Ally?

At first glance, ferns and their allies share a quiet, ancient presence on the prairie. Both reproduce by spores rather than seeds, and both are vascular plants—they have internal tissues for moving water and nutrients. However, the key difference lies in their leaves and stems. True ferns have fronds: large, divided leaves that unfurl from a coiled fiddlehead. Fern allies, such as horsetails and clubmosses, have simpler, often scale-like or needle-like leaves, and their stems may be jointed or creeping. When you are out with field notes, this distinction is your first clue.

Understanding this difference matters because it helps you identify what you are seeing without disturbing the plant. On a quiet morning, take a moment to observe the shape: if the plant looks like a feathery green plume, it is likely a fern. If it resembles a leafless, jointed green stalk or a tiny pine tree, you are looking at a fern ally.

How to Tell Them Apart by Structure

Follow these steps when you encounter a spore-bearing plant on the prairie:

1. Check for fronds. True ferns have large, often divided leaves called fronds. They emerge as fiddleheads in spring.
2. Look at the stem. Horsetails have hollow, jointed stems with a rough texture from silica. Clubmosses have creeping stems covered in small, scale-like leaves.
3. Find the spores. Ferns usually produce spores in clusters called sori on the underside of fronds. Horsetails bear spores in a cone-like structure at the stem tip, while clubmosses have spores in a cone or at the base of leaves.
4. Note the season. Both groups are most visible in spring and summer, but their dried stalks may persist into fall.

By taking these notes, you will build a personal field guide that grows with each season.

Examples of Ferns and Fern Allies on the Prairie

When you walk through a prairie remnant, you may encounter several examples of ferns and fern allies. Here are some common ones, along with what you can notice.

Typical Prairie Ferns

Prairie ferns often grow in moist draws or shaded edges. The lady fern (Athyrium filix-femina) has delicate, lacy fronds that arch outward. The ostrich fern (Matteuccia struthiopteris) forms tall, vase-shaped clusters with distinctive fertile fronds that turn brown in late summer. These are true ferns, with fronds and sori on the underside of the leaflets.

Ferns and Fern Allies Examples: Horsetails and Clubmosses

Two key fern allies on the prairie are horsetails and clubmosses. Horsetails (genus Equisetum) are among the most recognizable fern allies. The field horsetail (Equisetum arvense) sends up pale, fertile stems in early spring, followed by green, branched sterile stems that look like tiny bottlebrushes. Clubmosses, such as ground cedar (Diphasiastrum digitatum), creep along the soil with upright stems that resemble miniature conifers. Both are fern allies because they lack true fronds and reproduce by spores.

Use this table as a quick reference when you are out with your field notes. Remember that these plants are often small and easy to overlook; slow down and scan the ground carefully.

Why This Matters for Prairie Birdwatching

Ferns and fern allies are part of the habitat that birds rely on. For example, the dense growth of lady ferns can shelter ground-nesting birds, while horsetails often grow in wet areas that attract insects—a food source for warblers and sparrows. By recognizing these plants, you gain a deeper understanding of the prairie ecosystem and can predict where birds might be found.

As you prepare for your next outing, consider bringing a hand lens to examine spores and a notebook to sketch or describe what you see. Be respectful: avoid trampling plants, and stay on established trails when possible. The prairie is a delicate community, and patient observation yields the richest rewards.

In every season, from the first fiddleheads of spring to the brown stalks of autumn, ferns and fern allies offer a quiet lesson in resilience. Take time to notice their forms, and you will find that the prairie reveals itself in new ways.