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
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Fig.
7.3-3. Transverse section of vascular bundle of
ragweed (Ambrosia). The red band marked by the three arrows is part of a
simple perforation plate, but rather than lying parallel to the plane of
cutting, the plate is tilted upward and the microtome knife
passed right through it cutting most of it away and leaving only this
one piece. The six white dots (three are indicated by arrows) on the rim are
pits. The curved inner edge of the red band is the edge of the perforation
itself.
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