Up Primary xylem Oak wood Leaf vein Vein ends Bean seed Pine tracheids, xs Fern TE, xs Fern, TE, mag Annular walls Annular, stretched Annular, narrow Scalariform walls Scalar., narrow CBP, pine CBP, dicot CBP, irregular Contact faces Pits, side view CBP, pine, xs CBP,angio, xs CBP, fern, xs Contact face, xs Simple perf. plate 1 Simple perf. plate 2 Pitted perf. plate Perf. plate & helix Perf. plate, face Perf. plate, mag Perf. plate, section Perf. plate rim Perf. plate & wall Scalariform Per plate Primary xylem Vessel sizes Fern TE Pine needle VE precursor, ls Protoxylem 9 Contact faces VE precursor, xs Precursor 2 Torn vessel Torn vessel 2
| |
Fig.
7.2-3. Longitudinal section of vascular bundle in
a club moss (Lycopodium). The vessel elements with annular secondary
walls in corn (Figs. 7.2-1 and 2) are larger than those in most species. This
club moss also produces annularly thickened xylem cells – in this case
tracheids – that are narrow: this is a very high
magnification micrograph. Despite the magnification, the cells are so narrow
that almost no detail is discernable. This size is a somewhat more common than
that in corn.
|