What is the significance of lycopods, horsetails and ferns?

The role of ferns in nature and in human economic activity is mainly associated with deposits of coal formed by ancient ferns in the Carboniferous period of the Paleozoic. Modern ferns are used in medicine (for example, the male fern is used as an anthelmintic), as ornamental plants, in aquariums and reservoirs (for example, salvinia, azolla caroline). Some species of azolla are used as a green fertilizer that enriches the soil with nitrogen. In metallurgy, molds for casting are sprinkled with powder from the spores of these plants, and the metal parts easily come off the walls. In some areas of our country, spring horsetail shoots are eaten (raw, steamed and as a filling in pies), as well as young leaves of bracken fern. Bracken in the Far East is harvested in large quantities for food purposes. Horsetails are often malignant weeds; among them there are also poisonous forms.