Leaves |
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Leaf Anatomy |
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Types of Leaves |
Broad-leaved plants are usually described as having simple or compoundleaves, while narrow-leaved evergreens have needle-like, awl-shaped, or scale-like leaves. The following are examples of different leaf types. |
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Simple: not divided into leaflets; leaf composed of one blade. |
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Compound: consists of two or more leaflets. |
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Pinnately Compound: feather-like; leaflets along each side of a common axis. |
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Bipinnately Compound: primary and secondary divisions are pinnate. |
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Palmately Compound: 3 or more leaflets radiating from a common point. |
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Trifoliate: three leaflets. |
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Fascicle: cluster of needles arising from one point. |
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Single Needle |
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Scale-like |
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Awl-shaped: tapering to a slender stiff point. |
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Leaf Arrangement |
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Opposite: leaves are directly across from each other on the stem. Examples: Maple, Ash, Viburnum, Dogwood |
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Alternate: leaves are arranged singly at different heights and on different sides of the stem. Examples: Elm, Hackberry, Oak, Birch |
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Leaf Shapes |
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Cordate: heart-shaped. |
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Elliptic: broadest in the middle and narrower at each end. |
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Flabellate: fan-like. |
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Lanceolate: longer than wide, broadest below the middle and tapering to the apex. |
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Obovate: inversely ovate, broadest above the middle. |
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Ovate: egg-shaped, broadest below the middle. |
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Broad Ovate: wide, egg-shaped. |