Introduction to Lichen

Lichens are the symbiotic association of algal and fungal part so, are closely associated with each other.so, that they provide single body structure. Algal part is known as phycobiont. It prepares food for itself and for the fungal part also. Fungal part is known as mycobiont. It absorbs water and minerals and provides protection to the thallus. Thallus structure is irregular and variously coloured like black, brown, white, red, orange.

Occurrence

They have a wide range of occurrence. They are found in a various type of habitat like a tree trunk, branches of trees, fallen leaves, wall and leaf on the surface of a rock.

Types of Lichens

There are various types of lichens. They are as follows;

Crustose lichens

Crustose lichens are very thin and closely attached to substratum so, it is difficult to separate it from the substratum. They bear fruiting body, apothecia on the upper surface. Eg; Lecanora, Graphis. Lecanora, Graphis.

Foliose Lichens

Foliose lichens are much branched and folded and it forms leaf-like appearance. They are attached to substratum with the help of rhizine.

Fruticose lichens

They are much branched, erect, and pendulous structure. They bear fructose body at the tip of branches. Eg; Clodonia unsea

Economic Importance of Lichen

• It is the biological indicator of air pollution.
• It is the pioneer species of ecological succession.
• Species of Lecavora Parmelia can be used as food in different parts of the world.
• Parmelia perlatais used in snake bite.
• Species of Evernia, Roccella, Parmelia Racella montaignei is used in preparation of litmus paper.
• Species of Parmelia, Evernia, Evernia purnastris is mostly used in perfume making.