Allorhizia
The allorhizia is a rooting type of the dicotyledons ( dicotyledons ), which is opposed to the homorhizia .
If the root pole grows directly into a main root that develops more strongly than the lateral roots, such a root system is called allorhiz . The main root grows vertically into the ground (positive geotropic) and the first-order lateral roots branch off horizontally from this (plagiogeotropic) . If the growth of the main root is strongly promoted when the root system is enlarged, then one speaks of a taproot ; if it remains behind that of the lateral roots, of shallow root . The direction of the positive geotropic growth, analogous to the negative geotropic growth of the stem axis , is indicated by the starch grains, the statoliths , which are attracted by the acceleration of gravity .
The term is made up of the prefix állo (s) ( Greek αλλ ) “different” and rhizoma ( Greek ῥίζωμα ) “rooted”.
literature
- Ulrich Kull: Outline of general botany . Reprint of the 2nd edition. Schweizerbart, Stuttgart 2005, ISBN 3-510-65218-5 .