Search results
Results From The WOW.Com Content Network
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)
A leaflet (occasionally called foliole) in botany is a leaf-like part of a compound leaf. [1] Though it resembles an entire leaf, a leaflet is not borne on a main plant stem or branch, as a leaf is, but rather on a petiole or a branch of the leaf. [2] Compound leaves are common in many plant families and they differ widely in morphology. [3]
Some fronds are not pinnately compound (or simple), but may be palmate, costapalmate, or bifurcate. There is a spectrum from costapalmate to palmate. Costapalmate fronds are shaped like the palm of a hand and have a short midrib or costa. Palmate fronds are also shaped like the palm of the hand, but all ribs or leaflets arise from a central area.
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 ...
Rachis – main axis of a pinnately compound leaf. Sheath – the proximal portion of a grass leaf, usually surrounding the stem. Stipels – paired scales, spines, glands, or blade-like structures at the base of a petiolule. Stipules – paired scales, spines, glands, or blade-like structures at the base of a petiole. Stipuloid – resembling ...
Their leaves are typically grouped in umbrella-shaped arrangements at the tips of long erect branches. The leaves are carried on long petioles, and have conspicuous stipules. The leaves are very variable in shape, often palmately compound ( cf. subgenus Paniculata Strey ) [ 2 ] with leaflets likewise variable in shape, but also simple or palmate.
compound palmate Having leaflet s that radiate from a central point (usually at the top of a petiole), like spread-out fingers radiating from the palm of a hand. Compare palmate. compressed Flattened lengthwise, either laterally (from side to side) or dorsally (from front to back). concatenate Joined together in a chain-like form.
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".