Fern

Ferns are a fascinating group of plants that reproduce using tiny particles called spores instead of seeds or flowers. Unlike mosses and other simple plants, ferns have special tissues that help move water and nutrients through their bodies, making them more like trees and flowers in this way. Their leaves, known as fronds, often unfurl in a curled shape called a fiddlehead before opening up into beautiful, complex patterns.

There are about 10,560 different kinds of ferns known today, and they have been around for more than 400 million years. They first appeared during a time when many new plants were beginning to grow on land. Ferns are not usually grown for food or money, but some people use them for medicine, decoration, or to help clean up polluted soil. Certain ferns can even help add important nutrients to rice fields, which helps farmers grow more rice. Ferns also have special roles in many cultures and stories around the world.

Description

Ferns are special plants that don't grow flowers or seeds. Instead, they make tiny particles called spores to start new plants. Most ferns are not woody, meaning they don't have hard trunks like trees. Their leaves, often called fronds, can be simple or very divided into many smaller parts. Some ferns have different kinds of leaves—one type makes spores and another type just makes food for the plant.

The part of the fern that you see above the ground is called the sporophyte, and it has stems, leaves, and roots. Under the soil, ferns have structures called rhizomes or roots that help them get water and nutrients. Ferns also have a smaller stage in their life cycle called the gametophyte, which is like a tiny green plate that makes eggs and swimming cells that help fertilization happen.

Life cycle and reproduction

Ferns have a special life cycle with two main stages. First, the fern plant, called a sporophyte, makes tiny particles called spores in special clusters on the underside of its leaves. These spores are released into the air and land on the ground.

When the spores land on the ground, they grow into a small, independent plant called a gametophyte. This tiny plant makes male and female cells. A swimming male cell meets a female cell and joins with it, creating a new sporophyte plant. This new plant grows into the fern you see.

Taxonomy

Carl Linnaeus originally recognized 15 groups of ferns in 1753, placing them in a class called Cryptogamia. Since then, the number of known fern groups has grown significantly. Ferns have traditionally been classified in a class called Filices or in a Division named Pteridophyta. However, Pteridophyta is no longer considered a valid grouping because it includes different types of plants that do not share a common ancestor.

Ferns are also called Polypodiophyta or, when considered part of the vascular plants (Tracheophyta), Polypodiopsida. Traditionally, all spore-producing vascular plants were called pteridophytes, which included ferns and their close relatives. However, recent genetic studies show that some plants previously grouped with ferns are more distantly related. For example, clubmosses and spikemosses are now known to have evolved separately from other vascular plants. Modern research helps us understand how these plants are related and how they have changed over time.

The leptosporangiate ferns, often called "true ferns," make up most of the ferns we know today. Recent studies support the idea that a group called Osmundaceae split off early from other true ferns. Other classifications suggest that whisk ferns and ophioglossoid ferns form their own groups within the ferns.

Distribution and habitat

Ferns can be found all over the world, but they are most common in warm, tropical areas like rainforests. They grow less in cold places such as arctic regions. New Zealand, where ferns are a national symbol, has around 230 different kinds of ferns. Ferns are also frequently seen in forests across Europe.

Ecology

Ferns grow in many different places, such as tall mountains, dry deserts, and even underwater. They often thrive where flowers don’t, like in shady forests or on rocky surfaces. Some ferns live on the sides of trees, called epiphytes, and they provide a home for many tiny animals.

Many ferns need help from special fungi to grow, and some only grow in certain soil types. Fern spores are eaten by some animals, like mice and certain birds, because they contain nutrients like fats and proteins.

Uses

Ferns may not be as economically important as plants with seeds, but they are still valuable in many ways. Some ferns are eaten, like the young parts called fiddleheads from certain species such as bracken and ostrich fern. In places like Brunei, New Zealand, and the South Pacific, people have traditionally eaten tubers from ferns, including the king fern. Ferns are generally safe to eat and were used as food thousands of years ago.

Ferns are also useful in other ways. Small floating ferns called water ferns, or mosquito ferns, are used in rice fields to help provide nutrients for other plants. Many ferns are grown for decoration in gardens, homes, and as cut flowers, with popular choices including the Boston fern and staghorn ferns. Some ferns can become invasive and are considered weeds in certain areas.

Culture

The study of ferns is known as pteridology. During the Victorian era, people became very excited about ferns, collecting them and using fern designs in many types of decorative art, like pottery, glass, and textiles.

Ferns also appear in stories and traditions. In some cultures, finding a blooming fern is said to bring good luck and wealth. The Silver fern is a symbol of New Zealand, appearing on its passport and representing its national rugby team, the All Blacks.

Organisms confused with ferns

Some plants and even animals have names that sound like "fern" but are not actually ferns. For example, the asparagus fern is not a true fern but a type of flowering plant, and the air fern looks like a plant but is actually a group of animals related to jellyfish.

Other flowering plants, like some palms and plants in the carrot family, have leaves that look a bit like fern fronds. But unlike ferns, these plants make seeds inside fruits. Cycads also have leaves that look like ferns but belong to a different plant group called gymnosperms.