Plants and People

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Biology 328
Plants and People
Lab 5 Major Families II
http//www.desktopscenes.com/Scenes20from20Muir
20Woods20(2003)/slides/Path20to20the20Woods.ht
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Objective

• To familiarize you with vegetative and floral
  morphology of 2 families
• Grasses - Poaceae/Graminae
• Legumes- Fabaceae, Caesalpiniaceae, and Mimosaceae

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• Grasses - Poaceae

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Vegetative morphology

• Monocot
• Roots Fibrous
• Stem (Culm) Nodes and internodes
• Stem modifications rhizome, stolon/runner
• Leaves Sheath, lamina, ligule (outgrowth
  between sheath and lamina)

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Floral morphology

• Flower/Floret Basic unit, parts of 3s , highly
  reduced, non showy
• Perianth (calyx corolla) As lodicules at the
  base of the ovary.
• Stamens
• Pistil - Ovary, styles, and plumose stigmas
• 2 fertile bracts - Lemma (larger) and Palea
  (smaller)
• 2 or 3 florets Spikelet
• 2 sterile bracts - Glumes
• Fruit Grain/Caryopsis

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• Legumes- Fabaceae, Caesalpiniaceae, and Mimosaceae

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Floral morphology
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Todays lab
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Poaceae

• 1. Examine an oat (Avena) spikelet. Note the two
  basal glumes, which completely enclose the
  florets. There should be three florets above the
  glumes, with the terminal one not completely
  developed. Separate a palea from the lemma that
  encloses it. Is there any difference between a
  palea and a lemma? Also, observe the flower.
• 2. Diagram the oat (Avena) spikelet labeling
  glumes, florets, and the lemma and palea of one
  floret.
• 3. Examine and diagram a Bromus spikelet labeling
  the organs of its basic structure, i.e., glumes
  and paleas and lemmas of each floret.
• 4. Examine specimens of other grass genera on
  display.

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Legumes- Fabaceae Subfamilies Papilionoideae,
Caesalpinioideae, and Mimosoideae

• Compare the sample material with descriptions and
  terminology given in lecture and laboratory
  notes. For each floral sample, examine floral
  structure, paying close attention to the
  arrangement and structure of the androecium and
  perianth.
• Examine the legumes on display. Which of them
  are foods? Which of them are forage?

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Summary

• Todays Lab
• Familiarizing vegetative and floral morphology
  of grasses and legumes
• Next weeks lab
• Quiz - Major Families II
• Wood, paper and Cushing library