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Compound leaves may be pinnate with pinnae (leaflets) on both sides of a rachis (axis), or may be palmate with multiple leaflets arising from a single point. [1] Leaf structure is described by several terms that include: Bipinnate leaf anatomy with labels showing alternative usages A ternate compound leaf with a petiole but no rachis (or rachillae)
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.
[4] [5] "Frond" is commonly used to identify a large, compound leaf, but if the term is used botanically to refer to the leaves of ferns and algae it may be applied to smaller and undivided leaves. Fronds have particular terms describing their components. Like all leaves, fronds usually have a stalk connecting them to the main stem.
The leaves are pinnate (in the form of bird feathers, pinnae), with a central leaf stalk from which parallel "ribs" emerge from each side of the stalk, perpendicular to it. The leaves are typically either compound (with leaflets emerging from the leaf stalk as "ribs"), or have edges ( margins ) so deeply cut ( incised ) so as to appear compound.
Doubly pinnate; e.g. a compound leaf with individual leaflet s pinnately divided. bipinnatisect A pinnatisect leaf with deeply dissected segments. bisexual Bearing both male and female reproductive organs; usually, flowers with both stamen s and carpel s; synonymous with hermaphrodite, synoecious, and monoclinous.
The two main classes of compound leaf morphology are palmate and pinnate. For example, a hemp plant has palmate compound leaves, whereas some species of Acacia have pinnate leaves. The ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf is called a pinnule or pinnula.
The leaves are compound pinnate, 20–30 cm long, with 5-11 (mostly 7-9) alternately arranged leaflets; each leaflet broad ovate with an acute apex; 6–13 cm long and 3–7 cm broad, with an entire margin and a thinly to densely hairy underside. In the fall, the leaves turn a mix of yellow, gold, and orange. [citation needed]
Unlike most other maples (which usually have simple, palmately lobed leaves), Acer negundo has pinnately compound leaves that usually have three to seven leaflets. [8] Simple leaves are also occasionally present; technically, these are single-leaflet compound leaves.