Isidium

Isidie ​​(plural: isidia ) is a term from the lichen customer ( Lichenology ).

Isidia are outgrowths of the thallus surface of lichens, which serve as diasporas of vegetative propagation ( Lichens are symbioses of algae and fungus). They contain in the center of algal cells and are surrounded by a cortex formed by hyphae of the fungus. Their shape is very different artabhängig: isidia may be cylindrical pin -shaped, warty, limp, scaly, leaf-shaped, spatulate, be branched spherical or coral-like. Cylindrical isidia have 0.01 to 0.03 mm in diameter depending on the type and reach 0.5 to 3 mm in length. Older isidia break off easily and can, for example, transported by rainwater, wind or animals that grow on a suitable location for new lichens. 25 to 30 % of all genera of the leaf and shrub lichen develop isidia in lichens they are rare.

Other lichens occurring in vegetative propagules are soredia.