Transcript PLANTS - Georgia Organics

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
Adapted by Georgia Organics 2009
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
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.
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.
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
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.
BUDS
o A bud is an undeveloped shoot
o
o
o
o
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