Pinnate describes an arrangement of discrete structures (such as leaflets, veins, lobes, branches, or appendages) arising at multiple points along a common axis. For example, once-divided leaf blades having leaflets arranged on both sides of a rachis are pinnately compound leaves. Many palms (notably the feather palms) and most cycads and grevilleas have pinnately divided leaves. Most species of ferns have pinnate or more highly divided fronds, and in ferns the leaflets are typically referred to as pinnae (singular pinna). Plants with pinnate leaves are sometimes colloquially called "feather-leaved".
Odd and even pinnateEdit
Arrangements can be odd or even pinnate depending on whether the apical leaf is singular or in a pair.
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