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− | {{Wiktionary}}
| + | [[image:fern_frond_pinnate.jpg|right|thumb|200px|A '''pinnate''' frond of the fern, ''Blechnum appendiculatum''.]] |
− | '''Pinnate''' is a term used to describe [[feather]]-like or multi-divided features arising from both sides of a common axis in [[plant]] or [[animal]] structures, and comes from the [[Latin]] word ''pinna'' for "feather". A similar term is '''''pectinate''''', which refers to a [[comb]]-like arrangement of parts (arising from one side of an axis). The term contrasts somewhat with '''''[[leaf shape|palmate]]''''', in which the parts or structures radiate out from a common point. | + | Feather-like; with the [[leaflet]]s of a compound [[leaf]] placed on either side of the [[rachis]].{{SCH}} |
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− | [[image:fern_frond_pinnate.jpg|right|thumb|200px|A '''pinnate''' frond of the fern, ''Blechnum appendiculatum''.]]
| + | Types: |
− | Botanically, the term 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 [[Palm tree|palm]]s (notably the [[feather palm]]s) and most [[cycad]]s and [[grevillea]]s have pinnately divided leaves. Most species of [[fern]]s have pinnate or more highly divided [[frond]]s, and ferns the leaflets are typically referred to as "pinnae" (singular "pinna"). Plants with pinnate leaves are sometimes colloquially called "feather-leaved".
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− | '''pinnatifid''' – leaves with pinnate lobes that are not discrete, remaining sufficiently connected to each other that they are not separate leaflets. | + | '''pinnatifid''' |
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− | '''paripinnate''' – pinnately-compound leaves in which leaflets are born in pairs along the rachis without a single terminal leaflet; also called "even-pinnate". | + | '''paripinnate''' |
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− | '''imparipinnate''' – pinnately-compound leaves in which there is a lone terminal leaflet rather than a terminal pair of leaflets; also called "odd-pinnate". | + | '''imparipinnate''' |
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− | '''bipinnate''' – pinnately-compound leaves in which the leaflets are themselves pinnately-compound; also called "twice-pinnate". | + | '''bipinnate''' |
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− | '''tripinnate''' – pinnately-compound leaves in which the leaflets are themselves bipinnate; also called "thrice-pinnate". | + | '''tripinnate''' |
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− | '''tetrapinnate''' – pinnately-compound leaves in which the leaflets are themselves tripinnate. | + | '''tetrapinnate''' |
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− | [[Category:Plant morphology]]
| + | {{glossary}} |