This Pine leaf (better known as the pine needle) is from the genus Pinus, the “hard” or “yellow” pines. It is a diploxylon, which has two fibro bundles. The sheaths found on the needles are permanent (customarily).
Glossary:
Mesophyll: The soft fundamental tissue of the plant, that contains the chlorophyll, forms the thin-walled interior parts of a leaf.
Vascular system: The plant tissue consisting of ducts or vessels. In the higher parts of the plant, this forms the system by which sap is conveyed through the plant.
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