Isidie

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Pseudevernia furfuracea , especially in the middle of the camp, numerous fine pin-shaped isidia can be seen
Leptogium cyanescens with lobular isidia (microscope photo , enlarged 40 ×)

Isidie (plural: Isidien ) is a term from lichen science ( lichenology ).

Isidia are outgrowths on the thallus surface of lichens that serve as diaspores for vegetative reproduction (lichens are symbioses of algae and fungus ). They contain algae cells in the center and are enclosed by a bark formed by hyphae of the fungus. Their shape is very different depending on the species: Isidia can be cylindrical-pin-shaped, warty, lobed, scaly, leaf-shaped, spatulate, spherical or branched like a coral. Cylindrical isidia have a diameter of 0.01 to 0.03 mm and, depending on the type, reach 0.5 to 3 mm in length. Older isidia break off easily and can, e.g. B. transported by rainwater, wind or animals, grow into new lichens on a suitable surface. Isidia develop in 25 to 30% of all leaf and shrub lichen genera; they rarely occur in crusty lichen.

Other vegetative distribution units found in lichens are soredia .

literature

  • Georg Masuch: Biology of Lichen , Quelle & Meyer, Heidelberg / Wiesbaden (UTB f. Science), 1993, pp. 165/166, ISBN 3-8252-1546-6 .
  • Volkmar Wirth: The lichens of Baden-Württemberg . E. Ulmer, Stuttgart 1987, p. 507, ISBN 3-8001-3305-9 .