Bot. [mod. (Nägeli in Ger.) f. Gr. ξύλον wood: cf. PHLOEM.] Collective name for the cells, vessels, and fibers forming the harder portion of the fibrovascular tissue; the wood, as a tissue of the plant-body. Also attrib.
1875. Bennett & Dyer, trans. Sachs’ Bot., 94. The different forms of tissue of a differentiated fibro-vascular bundle may be classified into two groups, which Nägeli calls the Phloëm- (Bast) and Xylem- (Wood) portion of the bundle…. The xylem-portion of the fibro-vascular bundle has mostly a strong tendency to thicken its cell-forms. Ibid., 95. These horizontal elements … may be … designated as rays; within the xylem they are called xylem-rays, within the phloëm, phloëm-rays.
1894. D. H. Scott, Struct. Bot., I. Flowering Pl., 56. The woody character of the cell-walls of the xylem is due to the presence of a substance called lignine.
