What is a fern?

Frond ❯ Fern leaves are called fronds. These are usually divided into smaller sections, which increases the leaf’s surface area so it can capture more sunlight. Fronds not only carry out photosynthesis, using the energy from sunlight to make food for the fern, but they are also important for reproduction.

Pinna ❯ Each small segment of a fern frond growing from the central stalk, or rachis, is called a pinna.

Ferns are nonflowering plants that do not produce seeds. Instead, they reproduce using tiny spores, which are carried on the wind. Fern leaves are known as fronds, and they grow from underground stems. Spores are made on the underside of fronds.

Fiddlehead ❯ New fronds develop as tightly curled spirals called fiddleheads, which unfurl as the leaf grows.

Root ❯ The roots of ferns are very similar to those of flowering plants. They absorb water and nutrients from the soil and help anchor the fern into the ground.

Sori ❯ Spores are produced in brown structures called sori on the underside of the fronds. These sori can be arranged in speckles or lines, depending on the type of fern.

Rachis ❯ The top part of the stalk is known as the rachis. It is the backbone of the frond.

Stipe ❯ The stiff stem at the bottom of the plant is known as the stipe. It is often covered with scales or hairs, for protection.

Rhizome ❯ The main stem of most ferns is known as the rhizome. It sits either on the soil’s surface or just below, although in some tree ferns the stems can develop into a tall, woody trunk. The fronds of the fern emerge from the rhizome, which is often too short to be seen. Fossilized fern

Ferns first appeared almost 360 million years ago, among mossy swamps. Some large, treelike ferns had fronds as long as 93⁄4 ft (3 m). The fossil below shows an extinct fern that looks very similar to modern ferns, such as the male fern.

The comblike arrangement of leaflets earns this fern its name Pecopteris—the Greek word for comb.