Foliate lichen

The plant-like appearance of lichens hides their true identity. A lichen is not a single organism, but the result of a partnership (mutualistic symbiosis) between a fungus and an alga or cyanobacteria. Some lichens are formed of three or more partners. The body of a lichen consists of fungal filaments (hyphae) surrounding cells of green algae and/or blue-green cyanobacteria. The basis of the mutualistic symbiosis in lichens is similar to the mycorrhizal partnership between some species of fungi and the roots of most plants. The lichen fungus provides its partner(s) a benefit (protection) and gains nutrients in return.