Principles of Agricultural Science – Plant
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Principles of Agricultural Science – Plant
Leaf External Parts and Types
Unit 4 – Anatomy and Physiology
Lesson 4.4 Leave It to Leaves
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Forms of Leaves
Leaves come in many shapes and forms
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Leaf Parts
Can You Name
Them?
Blade
Tip
Base
Petiole
Margin
Secondary
Vein
Midrib
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Leaf Types
Leaves come in various sizes, colors, and
physical features.
You can use physical features to distinguish
among different species and varieties of
plants.
Leaf features assist with classification and
identification of plants.
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Physical Features of Leaves
Leaves have several physical features to
examine:
Simple versus compound
Shape
Venation
Margin
Tip
Base
Arrangement on stem
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Simple Versus Compound
Simple
Compound
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Leaf Shapes
Leaf shapes are listed on page 46 in the text
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Leaf Venation
Venation refers to how the veins are
orientated within the leaf structure
Parallel
Pinnate
Palmate
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Leaf Margin
The edges of the leaves provide clues also
Entire
Serrate
Dentate
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Leaf Tip
Several styles of leaf tips exist
Mucronate
Cuspidate
Obtuse
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Leaf Base
The location of where the petiole attaches to
the leaf blade is another point of reference
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Leaf Arrangement on the Stem
Arrangement of leaves on the stem provides
good clues. There are arrangements for
both simple and compound leaf structures.
Simple
Alternate
Simple
Opposite
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References
Parker, R. (2010). Plant and soil science:
Fundamentals and applications. Clifton
Park, NY: Delmar.
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