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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 .
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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 • A bud is an undeveloped shoot from which embryonic leaves or flower parts arise • A leaf budiscomposed 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