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The thallus ( plural thalli ; ancient Greek θαλλός thallós " young shoot , branch"), in English also camp , is the multicellular body of vegetation in plants and fungi, which is not divided into stem axis , root and leaf . Such plants are called thallophytes or storage plants. The thallus can only be negatively defined as multicellular or polyenergider vegetation body not the typical outline of a Kormus has .

The term thallus was introduced by Erik Acharius for lichen in 1803 . It is derived from the Greek θαλλός thallos "sprouting branch" (from θάλλειν "green, grow, bloom"). The term was quickly transferred to other groups of so-called lower plants.

In plants, the thallus is the level of organization below the corm . Mosses are among the plants with thallus . Due to the formation of stems ( cauloid ) and leaflets, the mosses have a special position, but are still thallophytes.

Some groups of algae , such as seaweed , and many representatives of fungi and lichens also have a thallus .

Thallus types

Tissue thallus in liverwort.

The simplest thallus is the cell or tube thallus : in some algae there are multinucleated giant cells (coenoblasts), which are referred to as siphonal organization type. Examples are Caulerpa among the Chlorophyceae and Botrydium and Vaucheria among the Xanthophyceae . Siphonal thalli also occur in the egg mushrooms , the Chytridiomycota and representatives of the yoke mushrooms . If the tubular thallus is divided by transverse walls, but the cells are multinucleated, this is the siphonocladal level of organization.

The thread thallus has a thread (trichal) structure. The shapes range from simple, unbranched threads ( spirogyra ) to branched threads and various cell differentiations to the flat thallus, which bears leaf-like structures ( phylloids , see phyllodes ).

Lichen thallus : Red algae often form complex structures. However, they do not form true tissue but plaiting materials ( Plektenchyme ). A woven fabric also occurs in the more highly organized fungi; the fruiting bodies are made up of woven fabric.

A tissue thallus occurs in candelabrum algae , brown algae and mosses.

supporting documents

Individual evidence

  1. Strasburger, 2002, p. 210.