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Sclerenchyma is the tissue which makes the plant hard and stiff. Sclerenchyma is the supporting tissue in plants. Two types of sclerenchyma cells exist: fibers cellular and sclereids. Their cell walls consist of cellulose, hemicellulose, and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation.
They are typically 1 mm (0.039 in) in length and are thus named fiberlike sclereids. These sclereids permeate the mesophyll as a dense mat. [ 5 ] During sclerification these fiberlike sclereid cells can increase by several hundred times their original size, compared to other parenchyma cells that only increase by two or three times.
The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. [ citation needed ] Although it is composed of non-vascular parenchyma cells, it's still considered part of the vascular cylinder because it arises from the procambium as do the vascular tissues ...
In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles. [1] The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural differentiation. [ 2 ]
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. [1] Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. [2]
In a vascular plant, the stele is the central part of the root or stem [1] containing the tissues derived from the procambium. These include vascular tissue, in some cases ground tissue and a pericycle, which, if present, defines the outermost boundary of the stele.
Sclerophyll woodland in Tuscany, Italy. The type of sclerophyllic trees in the Palearctic flora region include the holm oak (Quercus ilex), myrtle (Myrtus communis), strawberry tree (Arbutus unedo), wild olive (Olea europaea), laurel (Laurus nobilis), mock privet (Phillyrea latifolia), the Italian buckthorn (Rhamnus alaternus), etc. [4]
[1] A tracheid is a long and tapered lignified cell in the xylem of vascular plants. It is a type of conductive cell called a tracheary element. Angiosperms also use another type of conductive cell, called vessel elements, to transport water through the xylem.