Thallus

The thallus to German and stock, the multicellular body of vegetation in plants, which is not divided into stem axis, root and leaf. Such plants are called Thallophytes or storage plants. The thallus can only be defined negatively as multicellular or polyenergider vegetative body, does not have the typical structure of a corm.

The term thallus was introduced in 1803 by Erik Acharius for lichens. It is derived from the Greek thallos = budding branch from. The term was transferred to other groups of so-called Niederer plants quickly.

In plants, the thallus is the level of organization below the corm. The plant with thallus include the Moose. However, due to the formation of stems ( Cauloid ) and leaves the mosses have a special position, but are still Thallophytes.

Also a thallus have some algal groups, such as the algae, and many representatives of fungi and lichens. However, the last two groups are not among the plants.

Thallustypen

The easiest thallus is the cell or Schlauchthallus: some algae multinucleated giant cells ( Coenoblasten ) occur, which is called siphonaler organization type. Examples include the Chlorophyceae and Caulerpa in the Xanthophyceae Botrydium and Vaucheria. Next come siphonale thalli remains with the Eipilzen, the Chytridiomycota and representatives of Jochpilze. Is the Schlauchthallus divided by transverse walls, but the cells are multinucleate, this is the siphonocladale organization level.

The Fadenthallus is built up ply ( trichal ). The shapes range from simple, unbranched filaments ( Spirogyra ) via branched filaments and various cell differentiation up to the flat thallus bears the leaf-like structures ( phyllodes, cf phyllodes ).

Flechtthallus: red algae often form complex structures. However, they do not form true tissues but plaiting materials ( Plektenchyme ). A braided fabric also occurs in the highly organized fungi; the fruiting bodies are constructed of braided fabric.

A Gewebethallus occurs in the stonewort, in the brown alga, as well as in mosses.

Documents

• Gerhard Wagenitz: Dictionary of Botany. The terms in their historical context. 2nd expanded edition. Spektrum Akademischer Verlag, Heidelberg / Berlin 2003, ISBN 3-8274-1398-2, pp. 327f.
• Peter Sitte, Elmar Weiler, Joachim W. Kadereit, Andreas Bresinsky, Christian Körner: textbook of botany for colleges. Founded by Eduard Strasburger. 35th edition. Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-1010- X, pp. 210-217.