Plant Stem Anatomy

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Plant Stem Anatomy
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External Stem Anatomy
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Cross Section of Dicot Herbaceous Stem

• the vascular bundles are organized in a ring
• note the larger xylem cells
• note the compressed phloem
• note the vascular cambium between the xylem and
  phloem

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Monocot and Dicot Stem Comparison
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Cross Section of Dicot Woody Stem
The two major components are bark and wood. The
age of the tree can be determined by counting the
annual rings.
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Secondary Growth
This is growth in diameter where annual rings are
formed in wood. The bark contains the phloem and
cork while the wood is xylem. The boundary
between the two is the vascular cambium.
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Modified stems include

• runners, for asexual reproduction
• 2. rhizomes, for plant growth and food storage
• 3. tubers, for food storage in the form of starch

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