LICHENS

LICHEN 

Lichens are a symbiosis between a fungus and an alga,  they live together. They aren't plants, they are living things.

Algae can be unicellular or multicellular.They make their own food throught photosynthesis (sun, water and oxigen ) ,but they haven't organisms and tissues.

Fungi can be unicellular,for example yeast. They can be multicellular, such as mushrooms. They don't produce their own food. They are reproduced by spores. When spores are dispersed and these are found an alga, they are formed lichens.

Lichens grow anywhere of the earth's surface: on wood, rock, metal, plastic, cement, tree barc, tundra landscap, volccanic lava......

They can live in space, science experiment indicate that it's true.

• Alga provides food.
• Fungus gives the structure.
• Form a thallus, this is the body of lichen.  

Apothecium from  Parmelia,they look like to jam tarts.

                                                      CLASSIFICATION

           Crustose thallus: they live on rocks, glued to the  stone.

            Foliose thallus: they live on rocks, in branches or 

            sticks with the appearance of small leaves. 

            There are several types: Examples:

Parmelia

                 

         

Physconia

Xantoria

         Fructicose thallus: they live in branches, as small                 trees and they grow on the ground.

         Examples:

Ramalina

Cladonias: Look like a trumpet

Usnea

Evernia

Utilities

They are special organisms, they are very sensitive to air pollution. Lichens are used as indicators about the quallity of air.

Some of the photos were made by Daniel PANIAGUA RUEDA in the village of Carbajosa (Leon).

https://youtu.be/4_cgm6kh0ns