tracheid


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Fig. 299 Tracheid . General structure.

tracheid

any of several structures found in XYLEM, consisting of a cell which is long, slender and tapered with heavily lignified walls surrounding an empty lumen, the protoplasm having died.

The wall thickening can be continuous with BORDERED PITS, or else arranged in a variety of patterns, annular, helical and ladder-like. See Fig. 299 . Tracheids form the water-conducting tissues of GYMNOSPERMS, but are found also amongst the xylem vessels of ANGIOSPERMS

References in periodicals archive ?
Painting or coating of the wood member's lateral sides may also slow the process of air removal from wood tracheids, limiting the rate of liquid penetration.
Lateral wall pitting of vessels and vasicentric tracheids covered with alternate bordered pits (Fig.
It is not uncommon to find hyphae growing along the length of both vessel members (Figure 14) and vascular tracheids.
Scalariform perforations; ray Minquartia guianensis height over 1 mm, axial parenchyma diffuse and diffuse-in-aggregates, paratracheal scanty; vasicentric tracheids 8b.
1997 "Cambial development and tracheid length of dwarf pines (Pinus densiflora and P.
The inherent taxonomic interest of so many distinctive features in which Stixis resembles Forchhammeria seems clear: successive cambia, ray histology, tracheid presence, vestured pits, and crystal-bearing cells in conjunctive tissue.
Cavity formation and the exposure of peculiar structures in the secondary wall(S2) of tracheids and fibres by wood degrading basidiomycetes.
Evans, R, Downes, G, Menz, D, Stringer, S, "Rapid Measurement of the Variation in Tracheid Transverse Dimensions in a P.
Tracheid dimensions of the first formed cell rows (earlywood) were measured on microtomed transverse cut faces of juvenile and mature Norway spruce wood (Fig.
Herman M, Dutilleul P, Avella T (1998) Growth rate effects on temporal trajectories of ring width, wood density, and mean tracheid length in Norway spruee (Picea abies (L.
Vessels move more water efficiently than do tracheids because the perforations in their end walls are larger than the tracheid's pits and because the cross-sectional area is much greater.