What is a fern? It is a flowerless plant that has feathery or leafy fronds and reproduces by spores released from the undersides of the fronds. Ferns have a vascular system for the transport of water and nutrients. Uses. Ferns are not as important economically as seed plants but have considerable importance in some societies. Some ferns are used for food, including the fiddleheads of bracken, Pteridium aquilinum, ostrich fern, Matteuccia struthiopteris, and cinnamon fern, Osmundastrum cinnamomeum.