Ferns are consist of basic roots, stems and fronds. The fronds often consist of leaflets referred to as pinnae. Most are compound with a rachis and numerous pinnae On some or all of the leaves are the structures called sporangia. These are usually clustered into groups called sori, which are the visible dark round things on the bottom of the fronds. In many ferns a small leaf outgrowth called an indusium covers each sorus. They are "vascular plants" with well-developed internal vein structures that promote the flow of water and nutrients.
A sorus is a cluster of sporangia that appear on the back of ferns. Spores are sort of like seeds, but instead of growing into a baby fern, they grow into a gametophyte. They then produce either eggs or sperm which then fuse onto their opposites. After that the embryo becomes a young fern.
Did you know?
Ferns have fibrous roots that allow them to easily absorb all the water and nutrients. This helps them have a succesful growth.
Ferns are very old. They developed on earth about 400 million years ago.