Search results
Results from the WOW.Com Content Network
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which in some cases can store starch . In eudicotyledons , pith is located in the center of the stem.
Parenchyma is a versatile ground tissue that generally constitutes the "filler" tissue in soft parts of plants. It forms, among other things, the cortex (outer region) and pith (central region) of stems, the cortex of roots, the mesophyll of leaves, the pulp of fruits, and the endosperm of seeds.
Cross-section of a flax plant stem: 1. Pith 2. Protoxylem 3. Xylem I 4. Phloem I 5. Sclerenchyma 6. Cortex 7. Epidermis. 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]
In other vascular plants, the torus is rare. The pit membrane is separated into two parts: a thick impermeable torus at the center of the pit membrane, and the permeable margo surrounding it. The torus regulates the functions of the bordered pit, and the margo is a cell wall-derived porous membrane that supports the torus.
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 ( pith ) and a pericycle , which, if present, defines the outermost boundary of the stele.
Medullary rays, also known as vascular rays or pith rays, are cellular structures found in some species of wood. They appear as radial planar structures, perpendicular to the growth rings, which are visible to the naked eye. In a transverse section they appear as radiating lines from the centre of the log.
The inside of a tuber has the typical cell structures of any stem, including a pith, vascular zones, and a cortex. [citation needed] The tuber is produced in one growing season and used to perennate the plant and as a means of propagation. When fall comes, the above-ground structure of the plant dies, but the tubers survive underground over ...
Pith – the spongy tissue at the center of a stem. Chambered pith – a form of pith in which the parenchyma collapses or is torn during development, leaving the sclerenchyma plates to alternate with hollow zones; Diaphragmed pith – pith in which plates or nests of sclerenchyma may be interspersed with the parenchyma.