pith


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pith,

in botany, core of the stemstem,
supporting structure of a plant, serving also to conduct and to store food materials. The stems of herbaceous and of woody plants differ: those of herbaceous plants are usually green and pliant and are covered by a thin epidermis instead of by the bark of woody plants.
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 of most plants. Pith is composed of large, loosely packed food-storage cells. As the stem grows older the pith usually dries out, and in some it disintegrates and the stem becomes hollow. In trees the pith becomes much reduced as the woody tissue (xylem) grows. In East Asia, rice paper is made from the pith of some shrubs. Candlewicks are made of the pith of certain rushes.

Pith

The central zone of tissue of an axis in which the vascular tissue is arranged as a hollow cylinder. Pith is present in most stems and in some roots. Stems without pith rarely occur in angiosperms but are characteristic of psilopsids, lycopsids, Sphenophyllum, and some ferns. Roots of some ferns, many monocotyledons, and some dicotyledons include a pith, although most roots have xylem tissue in the center.

Pith is composed usually of parenchyma cells often arranged in longitudinal files. This arrangement results from predominantly transverse division of pith mother cells near the apical meristem. See Parenchyma, Root (botany), Stem

Pith

 

the central portion of a plant stem, consisting of loose parenchymatous tissue. The internal part of the pith sometimes ruptures with age, forming one large air cavity (Labiatae, Um-belliferae, some Gramineae) or several cavities (grape). Roots have no typical pith. Pith usually consists mainly of thin-walled cells, among which there may be lignified thick-walled cells (apple), latex vessels (Campanulaceae, Convulvulaceae), mucous cells (linden), or canals with volatile oils (Compositae, Umbel-liferae). The parenchymatous cells contain reserve starch, which in woody plants is concentrated mainly in external small-celled layers of the pith—the perimedullary zone. Druses or single crystals of calcium oxalate are often found in the pith.

pith

[pith]
(botany)
A central zone of parenchymatous tissue that occurs in most vascular plants and is surrounded by vascular tissue.

pith

pith
The soft central core of a log.

pith

1. the soft fibrous tissue lining the inside of the rind in fruits such as the orange and grapefruit
2. Botany the central core of unspecialized cells surrounded by conducting tissue in stems
3. the soft central part of a bone, feather, etc.
References in periodicals archive ?
In the ISO-1 and ISO-2 treatments, the pieces were glued on the tangential face of the outermost part of the blocks that were cut in the direction of the pith (Figs, 1b through 1d).
For example, the ruminal disappearance rates of DM, NDF, and ADF of leaf blade, ear husk, and stem pith were significantly higher than those of other corn stover fractions at 48 h and 72 h (leaf blade>ear husk>stem pith).
Damage type Tree species No damage (%) Color defect in pith (%) Silver birch 25.
If you need zest but find yourself without the right sort of kitchen tool, peel off large strips of zest with a standard vegetable peeler, leaving as much of the white pith behind as possible.
Her cool contains the pith of nineties sensibilities that Raphael strives to capture elsewhere.
It rights the defects of Donald Miller's chatterbox biography of 1989 by drawing out from Mumford's oeuvre the pith of his thought about building, planning and society.
Writing on behalf also of Justices Lorne Clark and Gordon Hart, in 1996 Justice Malachi Jones expressed the pith and substance of the appeal court's reversal as follows:
Using a serrated knife, pare the peel and pith from the oranges.
There is much to say for the pith of such a maxim, which snaps a retort to someone like Donovan Leitch proffering "Maybe I'm a lesbian.
On the back of a recent TreeTools (next to the pith helmets) you'll find bluebird and wood-duck nesting boxes made of wax-coated cardboard.