Thallus
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
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
- Gerhard Wagenitz : Dictionary of botany. The terms in their historical context . 2nd expanded edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2003, ISBN 3-8274-1398-2 , p. 327 f .
- Peter Sitte , Elmar Weiler , Joachim W. Kadereit , Andreas Bresinsky , Christian Körner : Textbook of botany for universities . Founded by Eduard Strasburger . 35th edition. Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-1010-X , p. 210-217 .
Individual evidence
- ↑ Strasburger, 2002, p. 210.