ns of pericycle:
0 Thick-walled pericycle gives mechanical support to the plants.
When composed of parenchymatous cells, it may act as storage organ of food materials.
(il) In dicot roots, the pericycle becomes meristematic and forms a part of the cambial ring. This
Cambial ring gives rise to the secondary tissues.
Pericycle gives rise to the lateral roots.
© Pith: It is also called medulla. It occupies the central part in dicot stems, dicot roots and monocot
Roots. In monocot stems, pith cannot be distinguished as vascular bundles are present through out the
Stem. Pith is generally composed of large parenchymatous cells with intercellular spaces present
Between them. Sometimes sclerenchymatous cells are also present in pith. E.g., Compositae.
Pith rays or medullary rays: These are the extensions of pith. In most dicotyledons, the peripheral
Layers of pith extend between the vascular bundles and are in contact with the pericycle. These
Extensions appear like rays and thus, they are called the pith rays. The pith rays are also called the
Ground tissue in leaves
The ground tissue is not differentiated into cortex and pith in the leaves. Ground tissue consists of thin-walled
Chloroplast containing cells and is called mesophyll.