Lichenes

Abstract

Although the majority of lichens are terrestrial, some grow in areas subject to salt spray and are a conspicuous feature of the upper reaches of many rocky shores. Some species are able to withstand daily submersion by the tide and are found in the eulittoral zone where they compete for space with other organisms, for example, barnacles and seaweeds. Lichens are complex plants comprised of fungal and algal components existing in what is believed to be a mutually beneficial association known as symbiosis. The exact nature of the relationship is still debated, but photosynthesis of the algal cells provides the fungus with organic nutrients, while the fungus provides the alga with support and protection.