Gynostemium
The gynostemium ( ancient Greek γυνή gyne = "woman" and stemon = "elevator" or "chain on the loom"), the stylus column or column , column and gynandrium , androstylium , is a special, often resupinated flower organ in plants. It arises from the fusion of one or more stamens with the stylus and the stigma . In order to mostly prevent self-pollination , the androeceum and the gynoeceum are separated by the beaks , separating tissue (rostellum).
A gynostemium occurs in the monocot plants only in orchids (there it is also called Columna ), Pauridia and Corsia , in dicotyledons it is found among others in the weft plants , easter luscious plants , Lopezia ( evening primrose plants ), the Apodanthaceae and the Rafflesia plants .
In the columna of the orchids, paired stelidia , column wings, and appendages can also be present at the upper end . Or there may be small, lateral ears , lobules (auricle). The anthers can also be in an anthers compartment, bowl (Clinandrium, Androclinium) in the upper part of the Columna. The anthers can also be covered with an anther shield (operculum).
It was specially developed for the weft plants ( Stylidium ), here it works, it snaps together when touched.
It is not to be confused with the tubular columna formed from the fused bases of the stamen tufts , e.g. B. in the Malvoideae , the androgynophore of the passion flower family or the gynostegium of the silk plant family .
literature
- 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 .
- Adrian D. Bell: Illustrated Morphology of Flowering Plants (= UTB . Volume 8089 ). Eugen Ulmer, Stuttgart (Hohenheim) 1994, ISBN 3-8252-8089-6 (English: Plant form . Translated by Josefine Schneidt).
