Ferns – a Different Sort of Plant

By Elaine Farragher


Being able to identify plants and animals is a satisfying and rewarding accomplishment. However, the task of learning the names of everything growing on our highways and byways can often seem so daunting that those interested give up before they even start.

It is often more fun and more satisfying to pick out one field of study and specialize in it. (However, some might still prefer to be jack-of-all-trades and master-of-none!)

An ideal field for specialization by the amateur naturalist is the ferns. They are among the more beautiful of plants, which makes them a pleasure to study, and there are really not that many different varieties; only about a hundred in all of Ontario. While this may sound like more than enough to keep one occupied, it is actually very few when you consider that the seed-bearing class of plants has over 300,000 species world-wide.

Ferns can easily be found in any casual walk through the woods. They lend grace and beauty to a great variety of habitats, from rather deep shade to bright sun; from rich soils to rocky, precarious cliffs; from very wet and swampy ground to relatively dry. It is usually easy for the casual observer to find half a dozen different ferns in a leisurely one hour stroll.

Ferns are of unique interest because they are a very primitive species dating from the time when dinosaurs reigned supreme and seed-bearing plants, with which the earth is now covered, had barely begun their ascendancy. At that time, ferns and their allies, the club mosses and horsetails, some of which were as large as trees, covered the earth. However, most of the ferns surviving today developed after the great coal age, about 100 million years ago, when seed-bearing plants were taking over as the dominant plant type.

The ferns’ method of reproduction is an interesting contrast to the seed-producers. Seed plants produce a flower in which male pollen must fertilize a female ovary to produce a seed. The fern reproduction begins with the spore which is neither male or female – it is asexual. If the spore finds the right conditions, it produces a tiny plant only a quarter of an inch in size. It is in this little plant, looking nothing like a fern (if you manage to see it at all) that the sexual life of the fern is played out. The plant produces both male and female organs at opposite ends. Just one of these tiny plants contains at least 20 female ovaries. When only one of them is fertilized, the others close up and the egg from which the adult fern will eventually grow, develops.

Ferns can produce an incredible number of spores in one season, sometimes millions on one plant. The common types of ferns, such as the marginal wood fern, grow sori or fruit dots on the underside of their leaves. One leaf of one plant might carry hundreds of these. Each fruit dot contains scores of spore cases and each spore case contains 64 spores. If they all managed to germinate – which most of them don’t – the result would be a mind boggling number of baby ferns.

Because the spores are so tiny and light, like mere dust in the wind, they can be over very long distances. As a result many species have a world wide distribution. About half the species found in our area can also be found in Europe. Although light, the spores are very hardy, able to withstand extremes of climatic conditions and most remaining viable for years until the exactly right conditions are met for development.

Once established, an adult fern can reproduce through creeping underground root stocks, for they are nearly all perennials. Ferns have their own rather unique way of growing up from these rootstocks. Unlike the seed-bearing plants that start small and keep adding leaves as the season progresses, the ferns rise up fully formed but tightly circled in the familiar fiddlehead. Gradually they uncoil as their leaves expand in a way that has always struck me a quite mechanical for a plant.

Another aspect of ferns that has always struck me as rather unplant-like is their veins. In the seed-bearing plants, the veins fork irregularly, in a haphazard way which seems more in keeping with the seemingly haphazard aspect of nature. But in ferns, the veins fork very regularly, into two equal parts, producing a very regular, rather geometric appearance.

Although regular in their growing habits, ferns have a beauty and diversity which makes them a highly satisfying plant to know and to study.


Elaine Farragher, September 1988


Subject headings

Ferns – Nature