modifications of roots, stems and leaves roots: a. bulbs and tubers for storage of food

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’