Once upon a time the ferns covered our entire planet. And they were huge trees! Ferns are flowerless green plants. Their featherlike leaves are called fronds. Young fern leaves are tightly curled. Ferns reproduce by dispersing spores instead of seeds. The spore cases, called sporangia are located in pockets on the margins of the leaves. There are about 12,000 different species of fern throughout the world. Some types first appeared on Earth more than 360 million years ago. Some species are free-floating aquatic plants, some species grow in moist woodlands, and a few species grow in arid or semiarid regions.
Ferns come in a wide variety of sizes and shapes.
Such animals as deer eat ferns, and some birds use them to line their nests.