Over a million years before nature produced flowers, the planet was colonized by ferns. They were established and thriving well before the age of the dinosaurs. Today, ferns are widely distributed around the world, though most species grow in tropical rain forests. Ferns grow on trees as epiphytes, as well as on the ground and in water.

Distinct from flowering plants that reproduce with seeds, ferns have a different reproductive system. Ferns reproduce by dust-like spores that fall to the ground to produce a new plant. Although the spores themselves are too small to be easily seen, look for the dots called sori on the undersides of the leaves. Present only on mature fronds (leaves), they contain sacs that hold the spores.