petiole

Examples of petiole in the following topics:

• Leaf Structure and Arrangment

  • Some leaves are attached to the plant stem by a petiole.
  • Leaves that do not have a petiole and are directly attached to the plant stem are called sessile leaves.
  • Leaves also have stipules, small green appendages usually found at the base of the petiole.
  • Petioles, stipules, veins, and a midrib are all essential structures of a leaf.

• Functions of Stems

  • The stalk that extends from the stem to the base of the leaf is the petiole.
  • The petiole is the stalk connecting the leaf to the stem.

• Types of Leaf Forms

  • A palmately compound leaf has its leaflets radiating outwards from the end of the petiole, like fingers off the palm of a hand.
  • (b) In palmately compound leaves, such as those of the horse chestnut (Aesculus hippocastanum), the leaflets branch from the petiole.

• Plant Responses to Wind and Touch

  • A tendril is a specialized stem, leaf, or petiole with a threadlike shape that is used by climbing plants for support.The meristematic region of tendrils is very touch sensitive; light touch will evoke a quick coiling response.

• Pressure, Gravity, and Matric Potential

  • This increases water potential between the water in the the petiole (base of the leaf) and in the leaf, thereby encouraging water to flow from the petiole into the leaf.

• Viroids

  • Symptoms in the leaf are uncommon, but include bleached veins and petioles.