Lichens - Characteristics

Description:

Lichens are mutual association between fungus and algae.

In lichens, Fungus performs three functions −

• Body structure and covering.
• Anchoring.
• Absorption of water and minerals.

Major function of algae is photosynthesis. Algae picks up water and mineral salts from the fungus while the fungus obtains part of the food made by algae. The relationship is a mutual association called symbiosis.

Lichens multiply by four methods −

• Progressive death and decay resulting in separation of lichens into two or more parts.

• Fragmentation is caused by mechanical injury.

• Isidia are superficial outgrowth of the lichens which are primarily meant for increasing surface area and photosynthetic activity.

• Soredia are microscopic lichen propagules produced in large numbers inside pistules.