Exercise 4

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Exercise 4

• Stems Woody Plants

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Introductory Notes

• Woody plants or a.k.a. perennials
• These plants live many years gaining in height
  and diameter each year depending on environmental
  circumstances

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Woody Dicots Introduction pg.36

• Highlight or underline
• Parenchyma tissue is the most abundant tissue in
  herbaceous plantsthese plants remain relatively
  soft as long as they live. However, the stems of
  woody dicots develop hard tissues very soon after
  the plants begin to grow.

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Page 36

• Highlight or underline
• Increase in diameter is caused by the formation
  of secondary tissues in the stem.
• These tissues develop through the activities of
  the lateral meristems or cambiums.
• Two types of cambiums may be presentvascular and
  cork.

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Goals
Highlight or underline 1,2,3,5,6 and 9
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External Features of a Woody Dicot
View next slide and answer 1-4
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Lateral Bud
Terminal bud
Lenticel
Bud scale scars
Bud Scale
Leaf Scar
Bundle Scar
Figure 4.1 Woody Twig
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Internal Anatomy of a Woody Twig

• Highlight or underline
• The tissues listed are from the center of the
  stem toward the exterior
• All bold typed words 1-6

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Observe then answer question 5
Summerwood
1 Annual Ring

Springwood
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• Highlight or underline 3
• Vascular rays are lines that radiate outward from
  the pith.
• Some rays become expanded when they reach the
  phloem and appear as masses of parenchyma.
• All of 4 and 5

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Cork cambium
Phloem
Secondary Xylem (1st2nd 3rd and 4th years growth )
Figure 4.2
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Cork
Expanded Phloem Ray
Phloem ray
Vascular cambium
Xylem ray
Annual ring
Summerwood
Springwood
Primary Xylem
Fig.4.2
Pith
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Questions

• 1. Dark non functional xylem in center
• 2. Light functional xylem around perimeter

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3. Contrast Sunflower/Tilia

• Sunflower

• Tilia

• Herbaceous
• Vascular Bundles
• Epidermis

• Woody
• Vascular Rings
• Cork

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Questions

• 4. Bud scale scars/annual rings
• 5. Contrast in size of early (spring) xylem
  (wood) and late (summer) xylem (wood)