Any of various small plants composed of a particular fungus and a particular alga (or blue-green alga) growing in an intimate symbiotic association and forming a dual plant, commonly adhering in colored patches or spongelike branches to rock, wood, soil, etc.
Webster's New World Similar definitions Any of various skin diseases characterized by papules and enlarged skin markings. Webster's New World Similar definitionsThe water moved silently over moss and lichen covered slabs of rocks, forming small pools in the low spots.
The reproductive organs of the lichen are of a typically fungal character, i.e. The thallus or body of the lichen is of very different form in different genera. An application of ' masonry biocide ' would then retard growth of algae and lichen.The whole site is biologically rich, with many woodland plant communities represented and rich bryophyte and lichen assemblages.