What is lichen? Write some important characters of lichens.

       Lichens are a specific group of primitive plants. A lichen is compost of two different components which are algae and fungi.
Both the components are involved in matual beneficial relationship. The algal component of lichen is known as phycobiont and the fungal component is known as mycobiont. The organisation neither resembles algae nor fungi but it is a symbiotic association. The fungal partner absorbs water, mineral nutrients and supplies those to the algal partner which can synthesize food materials.
   
        Some important characters of lichens are as follows:

1. Lichens are the composite association of algae and fungi.

2. Lichens reproduce both by asexual and sexual methods. Only the fungal component is involved in sexual reproduction.

3. The male sex organ is termed as spermogonium and the female sex organ is termed as carpogonium.

4. The growth of lichens is very slow.

5. The lichens are able to survive in high temperature and dry conditions for a long time.

6. Some species of lichens are used to produce medicines. Lobaria, Evernia, Peltigera etc. are used in whooping cough.