secondary xylem


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Related to secondary xylem: Secondary phloem

secondary xylem

[′sek·ən‚der·ē ′zī·ləm]
(botany)
Xylem produced by cambium, composed of two interpenetrating systems, the horizontal (ray) and vertical (axial).
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Bark was separated from secondary xylem and pith, and bark and wood were weighed separately fresh and after drying in a 60[degrees]C oven.
The secondary xylem development is also controlled by a crosstalk among different plant hormones [55, 65].
The basic cell types comprise the secondary xylem and another phloem.
Specimens of Dadoxylon recentium described from alluvial plain units at Joggins (Falcon-Lang 2003b) are identical to the secondary xylem of Mesoxylon cf.
Histochemical staining indicated the presence of a small amount of pectin in the primary walls and high concentrations of lignin in both primary and secondary walls of secondary xylem tissues.
The cortex and xylem measurements and the number of secondary xylem cells in the stem all increased across the nitrate levels (Table 2).
Abbreviations used in the figures in this study: 1 = primary xylem; 2 = secondary xylem (wood); A = aperture of bordered pit; C = vascular cambium; M margo; MX = metaxylem; P = pith; PB = pit border; PH = phloem; PM = bordered pit membrane; PX = protoxylem; R = ray; S sclereids; T = torus; TR = tracheid; TY = tyloses; V = vessel member.
The list of similarities between the two genera includes: vessels solitary or in small groups; helical sculpture on walls of vessels; vessel to vessel pitting alternate; vessel to axial parenchyma and vessel to ray pitting scalariform to transitional; pits non-vestured; scalariform perforation plates or modifications of them scarce, but present throughout the secondary xylem; imperforate tracheary elements are septate fibers with simple or vestigially bordered pits; axial parenchyma scanty vasicentric and terminal; bordered pits present on cross-walls of the strands of axial parenchyma; multiseriate rays wide, with tip and sheath cells upright but ray cells otherwise procumbent; uniseriate rays composed of upright cells.
For melina, many studies indicate that the variations in the anatomy of secondary xylem occurred in relation to tree age (Akachuku and Burley 1979, Akachuku 1985, Ohbayashi and Shiokura 1989, Nobuchi et al.
There are no reports of crystals in secondary xylem per se.
Histochemical and microscopic features of secondary xylem (Table 3, Fig.
The monocot secondary meristem produces most of the derivatives inner to the cambial cylinder with both the secondary phloem and secondary xylem lying on one side, which makes the growth essentially unidirectional (Philipson & Ward, 1965).