biology 23.3
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23.3 Stems
Point on a stem where a leaf is attached
Node
Region between nodes on plant stems
Internode
Plant structure containing undeveloped tissue that can produce new stems and leaves
Bud
Plant stem structure that contains xylem and phloem tissue
Vascular Bundle
Parenchyma cells inside the ring of vascular tissue in dicot stems
Pith
the type of plant growth that occurs at the tips of roots and shoots
Primary Growth
Pattern of plant growth in which stems increase in width
Secondary Growth
Lateral meristematic tissue that produces vascular tissues and increases the thickness of the stem over time
Vascular Cambium
Lateral meristematic tissue that produces the outer covering of stems
Cork Cambium
Older xylem near the center of a woody stem that no longer conducts water
Heartwood
Area in plants that surrounds heartwood and is active in fluid transport
Sapwood
Tree structure that includes all tissues outside the vascular cambium, including phloem, the cork cambium, and cork
Bark
In general, stems have three important functions: They produce leaves, branches, and flowers; they hold leaves up to the sunlight; and they transport substances between roots and leaves.
Key Concept
In monocots, vascular bundles are scattered throughout the stem. In dicots and most gymnosperms, vascular bundles are arranged in a cylinder.
Key Concept
Primary growth of stems is produced by cell divisions in the apical meristem. It takes place in all seed plants.
Key Concept
In conifers and dicots, secondary growth takes place in lateral meristematic tissues called the vascular cambium and cork cambium.
Key Concept
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