Shibu oli

Theophrastus (371-284BC) coined the term Lichen.

Lichenology is the branch of mycology that studies the lichens, symbiotic organism made up of a intimate symbiotic association of a microscopic algae with a filamentous fungus.

Lichens are the "dual or composite"organisms formed by the symbiotic associationbetween "algae and fungi".

They are the simple slow-growing plant that typically forms a low crusty, leaf-like or branching growth on rocks, walls and trees.

Example:

Peltigera Canina,Cristatella, Cretariaislandica,Parmelia(genus)