Ferns: Ancient Species Hiding in Plain Sight

Sunrise shining through the underside of a green-yellow plant with feather shaped leaves.

Ancient Species in the Watershed

The mention of pre-historic times often brings to mind enormous dinosaurs. Did you know some of the humble ferns of our watershed are as ancient as these giant reptiles? Or that, unlike the dinosaurs, they are still living among us today?

Ferns are among the oldest group of plants still alive today. They differ from other plants as they reproduce through spores. The wind carries these spores over long distances, allowing access to new habitats far from the original plant.

Common Ferns

You can find many ferns throughout the Credit River Watershed, here are some that are common:

Field Horsetail Fern

A beige-yellowish plant spore growing in the middle of other green plants.
Yellow spore form of field horsetail growing beside emerging green vegetative form.

Horsetails are unique looking plants with thin, hollow stems. Some horsetail species have branchless stems that resemble straws. Others have branches that spiral out from the center stem, resembling a horse’s tail.

The horsetails we see today are relatives of ancient tree-sized giants from 360 million years ago. Back then, they formed vast forests of thick stemmed plants growing up to 50 metres tall!

Field horsetails are a common sight across our watershed, growing in two distinct forms. The first form emerges around late April, where they produce spores at the top of yellowish stems. These stems quickly wither away, giving rise to a green stemmed plant with many thin, radiating branches.

Cinnamon Fern

A large bright green lace-like divided leafed plant bathed in sunlight.
Cinnamon fern soaking up the sun and thriving in a swamp.

Cinnamon ferns are a beautiful sight in wetlands. They grow in circular clumps of large leaves that reach three to five feet high! In the center of their leaves are cinnamon-coloured spores held up on tall, straight stems.

Cinnamon fern is among the oldest known living plant species on earth. Amazingly, through fossil records, scientists discovered this species has remained almost unchanged since the Jurassic period 180 million years ago. You can find these living fossils growing in many of our conservation areas, including Terra Cotta, Silver Creek and Rattray Marsh.

Bracken Fern

A green lace-like divided leafed plant growing parallel to a ground covered in plant litter.
Bracken fern growing at the edge of a forest trail.

Bracken may not appear to be a fern at first glance. With its large triangular leaves and tall stem, it looks like a few other fern species. Upon further inspection, you’ll see spores lining the underside of leaves.

Bracken is widespread across the world, growing on all continents except Antarctica. Similarly, you can find it across our watershed’s conservation areas, from Island Lake in the north to Rattray Marsh in the south.

Northern Maidenhair Fern

A cluster of bright green feather-shaped leafed plants covering a forest floor.
A cluster of maidenhair fern growing in a deciduous forest.

These ferns are called “maidenhair” because their leaves resemble thick hair cascading down a maiden’s shoulders. The dark stalk supports light green leaves that reach up to two feet tall.

Maidenhair ferns are an unmistakable sight of hardwood forests. To see these beautiful ferns in our watershed, head to Terra Cotta, Silver Creek or Limehouse Conservation Areas.

Ferns are a Watershed’s Best Friend

Ferns are important components of our watershed’s ecosystems. Their presence provides wildlife habitat, improves soil health and quickly colonizes new natural areas, filling them with vegetation. Ferns, being sensitive to ecosystem disturbances, serve as valuable bioindicators for ecologists assessing ecosystem health.

CVC’s Integrated Watershed Monitoring Program (IWMP) collects data on the health of plant species in our watershed. Through IWMP, we have gathered data on 28 of the 67 known fern species in our watershed! Keep a lookout for ferns on the trails and in our parks before the growing season is over.

Have you seen ferns while visiting our conservation areas? Share your photos with us on Instagram, Facebook, X and LinkedIn

By Joe Gabriel, Technician, Watershed Monitoring

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