modifications of roots, stems and leaves roots: a. bulbs and tubers for storage of food
TRANSCRIPT
Modifications of roots, stems and leaves
Roots:A. Bulbs and tubers for storage of food
B. Prop roots: Provide additional anchorageand support for the plant.
Corn
C. For vital functions:
• Haustoria or sucking roots of Cuscuta
Get nutrients fromthe host plant
•Respiratory roots or Pneumatophores
Spongy outgrowthsof roots below.Help gases diffusethrough pores on theupper end of the roots
• Floating roots – help plant float and also withrespiration.
• Aerial roots - Not parasiticHelp absorb moisture from the air and make it available to the plant.
2. Stems:
A.Storage of food – Example tubers in potatoes,Sweet potatoes
B. Bulbs in onions
• Corms in Crocus:
B. For climbing:
C. Asexual reproduction
Stolon
D. Cladodes or cladophylls:
Store water and help the plant with photosynthesis
Stem
3. Leaves:
• Modified to spines or thorns for protection againstpredators and to minimize water loss through
transpiration.
Thick cuticle to store water such as the Agave plant found in the desert.
• Pine trees have needle-like leaves to adapt to the cold climate. Thick waxy epidermis protects from
cold damage. Sunken stomata reduce water loss.
Adhesive disc/Hold fast – use for climbing.Example – Boston ivy
• Specialized, highly colored leaf below the flowerto lure pollinators. Called a bract.Example: Poinsettia and dogwood
Flower
Floral bracts
Thorns – Protection – Example Roses, Pyracantha
Tendrils – Used for climbing or to attach to objects.Example: Virginia creeper, Peas, Grapes
Leaves modified to lure, trap and digest insects.
Examples: Pitcher plant, Venus fly trap, DroseraInsects provide extra nitrogen to the plants.
http://natgeotv.com/ca/built-for-the-kill/videos/plants_eating_bugs
Succulent leaves – Lithops ‘ Living stones’