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| The Vascular Bundles are found opposite to
the ribs. They are arranged in one circle around the circumference of the Cortex. Each bundle contains Phloem & Xylem. This type of Stele is a Eustele which is typical for dicots. Each Vascular Bundle contains a "Carinal" Canal. This is caused by the destruction of xylem during stem Elongation. We can call these Vascular Canals. Studies have shown that these can actually conducts water, however, this can't be very efficient. |
 Partial Cross Section of Equisetum Stem
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| The first-formed Xylem is
called Protoxylem. This is destroyed by stem elongation and
is represented by the Vascular Canal. The later-formed Xylem is called Metaxylem. This brackets the Phloem. This arrangement is called Bicollateral & is also typical for dicots. The Xylem contains Tracheids and Vessel Members. Vessel members are thought to be Advanced because they are found in flowering plants and because they are more efficient for water conduction. Consequently, the Stele in the stem shows a lot of advanced traits with regards to the Vascular Bundles. |
 Vascular Bundle stained with Toluidine Blue: The Xylem is Blue & flanks the Phloem. The cavity is the Vascular Canal. This is where the protoxylem has been destroyed due to rapid elongation.
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| The Phloem is formed opposite the Xylem. However, the Metaxylem cradles the Phloem. Sieve Cells are present. These resemble Sieve Cells in more advanced taxa & they contain Callose in their Sieve pores. |  |
