Haustorium

A haustorium ( Mz haustoria ) is a suction device on nutrient intakes, with which a plant or fungus absorbs substances such as water or nutrients from another part of their own individual or by a foreign organism. Haustoria are of very different nature:

• Parasitic seed plants with haustoria penetrate into the host plant, and call its vascular bundles on.
• In fungi, especially in the lichen- forming, single hyphae can be formed as haustoria. In the lichen, the Pilzhaustorien lay close to the algal cells ( appressorium ) or even penetrate a little into it. Parasitic fungi penetrate the haustoria into host cells.
• At the foot of the mosses Sporogons haustorium is called. With him the Sporogon sitting in gametophytes and takes away from this nutrients.
• The embryo of the Ferns also forms a foot, called haustorium, from, with whom he is in the prothallus.
• Also in the embryology of angiosperms there are Haustorienbildungen, formed from parts of the embryo sac, the embryo or the endosperm.

Haustorium of parasitic flowering plants

Most parasitic flowering plants have transformed their roots to haustoria, such as the mistletoe. A few make their haustoria shoot tissues, such as the devil twists ( Cuscuta ).

The haustoria penetrate into the tissues of the host plant where they are happy to hang vascular bundles. There are tapped both xylem as well as phloem. The mass transfer to the phloem is likely at least partly Plasmosdesmen, so symplastically done. The mistletoes represent the tissue contact her by a Adhäsionsepithel. Its cells resemble secretions hair. When the devil twisting the haustoria embrace the sieve tubes of the host plant like fingers.

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, p 137