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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)
paripinnate: pinnately compound leaves in which leaflets are borne in pairs along the rachis without a single terminal leaflet; also called "even-pinnate". imparipinnate: pinnately compound leaves in which there is a lone terminal leaflet rather than a terminal pair of leaflets; also called "odd-pinnate".
[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.
The middle vein of a compound leaf or a frond, when it is present, is called a rachis. Palmately compound The leaflets all have a common point of attachment at the end of the petiole, radiating like fingers of a hand; for example, Cannabis (hemp) and Aesculus (buckeyes). Pinnately compound Leaflets are arranged either side of the main axis, or ...
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.
Petiole – a leaf stalk supporting a blade and attaching to a stem at a node. Petiolule - the leaf stalk of a leaflet. Pulvinus – the swollen base of a petiole or petiolule, usually involved in leaf movements and leaf orientation. Rachilla – a secondary axis of a multiply compound leaf. Rachis – main axis of a pinnately compound leaf.
Desmoncus leaves are pinnately compound and are made up of a leaf sheath, petioles, rachis, and individual leaflets. The ends of the leaves are modified into a climbing structure called a cirrus. The ends of the leaves are modified into a climbing structure called a cirrus.