Plant Profile: Ferns

By Diane Willis

Reprinted from The Understory, Oct.–Nov. 1999

Illustration © Cathy Vogelsong

In Florida, there are many species of ferns, most of which are found in swamps and shady hammocks. One species, bracken fern (right), is found in open pine flatwoods.

Ferns are some of the most primitive plants. The first land plants were algae that survived in tidal pools close to the ocean. Then came the liverworts, flat, paper-thin plants without roots (some have threadlike holdfasts whose only purpose is to anchor them to the substrate, which is usually rocks or trees). Liverworts absorb water through all the plant parts and cannot survive in full sun or dry areas. Then the mosses evolved, with true roots that can convey water from the soil to the leaves, but without a vascular system, so the plants can't grow more than one foot high. After that, horsetails and club mosses evolved, with not only roots, but stems with special tubers for carrying water to the leaves. These plants were treelike during ancient times, reaching 60-100 feet tall.

Ferns are one step above horsetails and club mosses, with tougher roots and sturdier stems. During ancient times, ferns were treelike, with woody trunks up to 50 feet tall, and they were the dominant vegetation in some areas. Treelike ferns as big as that or even bigger are present today in rain forests in South America, Australia and the Pacific Islands. Most of the fern species are found in tropical regions that are not subjected to freezing temperatures or in subtropical or mountain rain forests. However, about 15% of the world's species do grow in temperate forests and a few even in alpine or tundra. About 5% of the world's fern species grow in temperate grasslands, semiarid or desert regions (usually along streams, wetlands or rock outcrops). Most ferns grow on soil or rock, but especially in tropical or subtropical regions, they can grow on tree trunks or branches.

The biggest difference between ferns and flowering plants is the evolution of flowers and seeds. Seeds have a multicelled embryo encased in a protective covering along with stored food. Ferns produce spores that are usually only one cell, the biggest of which is only one five-hundredth of an inch in size. Ferns can release hundreds to thousands of dust-like spores. In old Europe, some people were convinced that ferns did produce seeds, but that nobody had seen them because they only appeared briefly at midnight on one day of the year, which was midsummer eve. People used to go out in woods in the middle of the night looking for fern seeds, because legend had it that fern seeds had magical powers, and could make you invisible or give you second sight.

Fern buds (fiddleheads) have been eaten in salads and soups and are reputed to taste like asparagus. Some settlers made them into flour for bread. In the Orient, fiddleheads are eaten extensively and may be one of the causes of the high rates of stomach cancer there. Bracken fern has been linked to cancer in grazing animals. Ferns have been used to make medicines, dyes, as thatch for roofs and bedding for cattle. American Indians boiled roots of bracken fern to use in weaving.

Published on  07.30.2012