Modifications of roots, stems and leaves

Modifications of roots, stems and leaves Roots: A. Bulbs and tubers for storage of food

B. Prop roots: Provide additional anchorage and support for the plant. Corn

C. For vital functions: • Haustoria or sucking roots of Cuscuta Get nutrients from the host plant

Respiratory roots or Pneumatophores Spongy outgrowths of roots below. Help gases diffuse through pores on the upper end of the roots

Floating roots – help plant float and also with • respiration.

Aerial roots - Not parasitic • Help absorb moisture from the air and • make it available to the plant.

2. Stems: • 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: Stem Store water and help the plant with photosynthesis

3. Leaves: • Modified to spines or thorns for protection against • predators 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 flower • to lure pollinators. Called a bract. • Example: Poinsettia and dogwood Floral bracts Flower

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, Drosera Insects provide extra nitrogen to the plants. http://natgeotv.com/ca/built-for-the-kill/videos/plants_eating_bugs

Succulent leaves – Lithops ‘ Living stones’

Modifications of roots, stems and leaves