simple leaf

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Diagram showing various fern leaf types, including simple, once-divided, falsely dichotomous, and palmate leaves, examples of leaf venation patterns, and cross-sections of petioles illustrating internal vascular arrangements.

Leaf morphology

simple leaf

plant anatomy

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July 13, 2026

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Diagram showing various fern leaf types, including simple, once-divided, falsely dichotomous, and palmate leaves, examples of leaf venation patterns, and cross-sections of petioles illustrating internal vascular arrangements. — fern leaf anatomy and morphology Fern leaves, showing leaf types, leaf venation, and internal petiole vascularization.

A simple leaf is a leaf whose blade is not divided to the midrib, even if it is lobed. Leaves originate from cell divisions in the shoot apical meristem and grow to form a leaf primordium. The shape of simple leaves, including lobed forms, is determined by differences in the activity of marginal meristems.12

The anatomy of a leaf reflects its environment. Mesomorphic leaves are suited for moist conditions, xeromorphic leaves for dry conditions, and hydromorphic leaves for aquatic environments. Leaves are a primary organ of the angiosperm body, along with roots and stems, and are crucial for photosynthesis.23

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angiosperm
Leaves
…petiole, the leaf is called simple. Simple leaves may be variously lobed along their margins. The margins of simple leaves may be entire and smooth or they may be lobed in various ways. The coarse teeth of dentate margins project at right angles, while those of serrate margins point toward…
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…petiole, the leaf is called simple. Simple leaves may be variously lobed along their margins. The margins of simple leaves may be entire and smooth or they may be lobed in various ways. The coarse teeth of dentate margins project at right angles, while those of serrate margins point toward…
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Fabales
Cercideae and other subfamilies
…which the leaves are apparently simple and often bilobed. The flowers of Cercis are only superficially similar to those of Faboideae.
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…which the leaves are apparently simple and often bilobed. The flowers of Cercis are only superficially similar to those of Faboideae.
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Fabales
Characteristic morphological features
The simple leaves of some are presumably reduced from the compound forms. The most striking of these modified leaf forms are the several hundred species of Australian Acacia, in which the apparently simple leaf represents the flattened and modified axis of a compound leaf. Stipules, a…
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The simple leaves of some are presumably reduced from the compound forms. The most striking of these modified leaf forms are the several hundred species of Australian Acacia, in which the apparently simple leaf represents the flattened and modified axis of a compound leaf. Stipules, a…
Read More

Sapindales
Characteristic morphological features
…from the petiole apex) or simple. Leaves are generally alternately arranged along a stem and are only rarely opposite or whorled. An interesting form of leaf is found in Citrus, where the simple blade is separated from the petiole by a joint. Because this type of leaf occurs in other…
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…from the petiole apex) or simple. Leaves are generally alternately arranged along a stem and are only rarely opposite or whorled. An interesting form of leaf is found in Citrus, where the simple blade is separated from the petiole by a joint. Because this type of leaf occurs in other…
Read More