Plant Morphology

1
Plant Morphology

• By
• Holly NeeSmith
• Stephanie Gilliam

Provided by Dr. James Corbett, Agriculture
Teacher, Lowndes Co. High School GA Ag Ed
Curriculum Office To accompany Georgia
Agriculture Education Curriculum July 2002
2
Leaf Structure

• A leaf is held away from its stem by a stem-like
  appendage called a petiole.
• The base of the petiole is attached to the stem
  at a node.
• The blade is the expanded thin structure on
  either side of the midrib and is usually the
  largest, most conspicuous part of a leaf

3
Leaf Parts

• The cuticle is part of the epidermis
• It produces a waxy layer called cutin, which
  protects the leaf from dehydration and disease.
• On the top and bottom is a layer of thick, tough
  cells called the epidermis. Its primary function
  is to protect the other layers of leaf tissue.

4
Leaf Parts Continued

• Special epidermal cells called guard cells open
  and close in response to environmental stimuli,
  such as changes in weather and light.
• They regulate the passage of water, oxygen, and
  carbon dioxide into and out of the leaf through
  tiny openings called stomata.
• Located between the upper and lower epidermis is
  the mesophyll.
• Located within the mesophyll cells are
  chloroplasts, where photosynthesis takes place.

5
Roots

• The roots help to provide support by anchoring
  the plant and absorbing water and nutrients
  needed for growth.
• They can also store sugars and carbohydrates,
  which the plant uses to carry out other
  functions.
• Plants can have either a taproot system (such as
  carrots) or a fibrous root system

6
Stems

• Stems carry water and nutrients taken up by the
  roots to the leaves.
• The food produced by the leaves moves to other
  parts of the plant.
• The cells that do this work are called the xylem
  cells (move water) and phloem cells (move food).
• Stems also provide support for the plant,
  allowing the leaves to reach the sunlight they
  need to produce food.

7
BUDS

• A bud is an undeveloped shoot from which
  embryonic leaves or flower parts arise
• A leaf bud is composed of a short stem with
  embryonic leaves
• A flower bud is composed of a short stem with
  embryonic flower parts.
• Buds are named for the location they inhabit on
  the stem surface.
• Enlarged buds or parts of buds form the edible
  portion of some horticultural crops