Radial section: five axial parenchyma strands and one septate fiber; pits on cross-walls of axial parenchyma are numerous and bordered, c-e Solmsia calophylla Baill., McPherson 5511 (MO), c, d SEM images of cross-walls of axial parenchyma strands in radial section, to show a single bordered pit
in each, e Transverse section, outer face of cross-wall of axial parenchyma; all pits are bordered, f Gnetum gnemon, Carlquist 8088 (RSA).
pairs control movement of water from one tracheary element to the next in the wood of vascular plants (Zimmermann, 1983; Pittermann et al., 2005).
Mechanical tissue is composed of fibre with distinctly bordered pit
(fibre-tracheids), numerous, occasionally septate fibres with simple pits, of medium length, sometimes with helical thickenings (Metcalfe and Chalk, 1983).
polystachyum Ho + - Podocarpus costaricensis Ho - - Podocarpus guatemalensis Ho - - Podocarpus macrostachys Ho - - Prioria copaifera Ht - - Prumnopitys standleyi Ho - - Qualea paraensis Ho-Ht - S(+)v Sclerolobium costaricense Ho - - Sideroxylon capari Ht - U+ P(-) Swietenia humilis Ht +- U+ P(-) Swietenia macrophylla Ht +- U+ (-) Tabebuia guayacan Ho + - Tachigali versicolor Ho - S(+) Vantanea barbourii Ht - - Fiber: FL=Fiber or tracheids length (mm), LD=lumen or tracheids diameter (um), WCT=wall cell thick (um), FC=Fibers crystals, SF=Septate fibers, GTF=ground tissue fiber, SBD=simple to minutely bordered pits
, BD=Fibers with distinctly bordered pit
, T=tracheids, PFRT=Fiber pits common in both radial and tangential, FS=Fibers stored.
Yuzou Sano's chapter on bordered pit
structure and resistance to cavitation is worthy of a wide audience, because it covers structures and processes basic to the successful functioning of wood.
Many studies have shown that the increased permeability occurring during water storage of logs is a result of the decomposition of bordered pit
membranes, ray parenchyma cells, and resin canals by bacterial action (Knuth and MeCoy 1962, MacPeak 1963, Greaves 1969).
pairs connect water-conducting tracheary elements of vascular plants and allow water transport from one element to the next.
Effect of bordered pit
torus position on permeability in Chinese Yezo spruce.
Frequently, the pit membrane is aspirated and the torus blocks one of the apertures of a given bordered pit
pair (compare Figs.
Thus, bordered pit
pairs provide passageways for water moving from cell to cell.
1), and it is the pits between tracheary elements (the so-called bordered pit
However, below 25 percent MC, drying rates of untreated samples were lower than steam-treated samples because steam treatments enhanced vapor permeability of wood by damaging bordered pits
, aspirated pits, and chemical structure of the cell-wall.