| Vessel elements, tracheids, fibres, sieve tube elements, sieve cells, and parenchyma cells are the major components of vascular tissue. |
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| Lignins occur in great quantity in the secondary cell walls of fibres, xylem vessels and tracheids. |
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| Archaeosigillaria had an exarch actinostele with scalariform and reticulate tracheids. |
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| In conifers, the tracheids, which account for most of the wood, give the tree rigidity and form most of the xylem. |
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| In the rays, they operate as transverse tracheids transporting water and mineral nutrients in a radial direction. |
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| The tiny tracheids are no more than a few millimetres long and range in diameter from one-tenth to one-hundredth of a millimetre. |
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| Pits at the intersection fields of cells of radial parenchyma with longitudinal tracheids are pine-like type with small flanges. |
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| However, it should be noted that tyloses are reported in tracheids of some species of Pinus and even in such cell types as fibre-tracheids or laticifers. |
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| Graniferous tracheary elements, which may be either tracheids or vessel members, have been observed most often in the haustoria of root-parasitic angiosperms. |
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| It can be seen in Fig 3b that the tracheids are pulling apart along their centre lines. |
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| Sporadic pitting is present but only in the last few rows of latewood tracheids. |
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| From there the fungus colonizes the tracheids of the xylem and grows axially and vertically up to the root crown and further up the stem. |
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| This method allows the cavitation resistance of the metastable liquid water in the lumen of tracheids in conifer sapwood sections to be estimated. |
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| Main conductive tissue for water and dissolved minerals in vascular plants, characterized by the presence of tracheids. |
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| The tracheids of earlywood formed at the beginning of a growing season have large radial sizes and smaller, thinner cell walls. |
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| There are no pits at the tangential walls of the summer tracheids. |
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| The xylem showed incurved margins and consists of scalariform tracheids and parenchyma cells. |
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| Cut surface of maple showing vessels, rays and tracheids. |
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| Fibres from those conifers also labelled tracheids are distinguishable by the number, form and disposition of the pit-pairs that they have, which can be single or bordered. |
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| This discoloration tends to be localized to a number of small groups of vessels and tracheids, so appearing as a series of longitudinal brown stripes when the cortex is removed. |
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| Radial tracheids are serrated with isolated teeth. |
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| Cell structures in Norway Spruce, showing tracheids and ray cells. |
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| This desiccation appears to result from the secretion of a hydrophobic resin into the tracheids, causing the embolism of these conducting elements near the inoculation point as the infection evolves. |
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| Protoxylem tracheids have helices with borders in Huperzia and Lycopodium, but in Phylloglossum protoxylem annuli and helices are non-bordered. |
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| Flooding also induces the formation of short, thick-walled rounded tracheids, surrounded by intercellular spaces. |
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| Finally, the latewood tracheids are formed, with small radial sizes and greater cell wall thickness. |
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| The movement of water out of the leaf stomata creates a transpiration pull or tension in the water column in the xylem vessels or tracheids. |
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| In contrast, the xylem of angiosperms comprises both tracheids and long, tubular vessels. |
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| In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. |
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| Then, the first tracheids of the transition zone are formed, where the radial size of cells and thickness of their cell walls changes considerably. |
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| They were then polished with progressively finer sandpaper to improve clarity of the tracheids and make the tree rings clearer and more easily distinguishable. |
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| The anatomy was simple, the central strand of sclerenchyma of the algal progenitors becoming a strand of tracheids forming the earliest type of stele, the protostele. |
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| However, by the time they become competent to conduct water, all xylem tracheids and vessels have lost their cytoplasm and the cells are therefore functionally dead. |
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| Tracheids of Lycopodium were studied by Bierhorst and by Wilder by means of light microscopy. |
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