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A stipule is "interpetiolar" if it is located in between the petioles, as opposed to being attached to the petioles, and generally one stipule from each leaf is fused together, so it appears that there's just one stipule between each leaf. [6] A stipule is "intrapetiolar" if it is located in the angle that is between a stem and a petiole. In ...
(of a compound leaf) Having precisely two leaflet s, usually in a symmetrical pair, e.g. a leaf of Colophospermum mopane. Compare jugate lobed leaf, e.g. most species of Bauhinia. bifusiform Fusiform with a pinch in the middle. bilabiate Having two lips, e.g. the form of the petal s in many irregular flowers. bilateral 1.
A stipule, present on the leaves of many dicotyledons, is an appendage on each side at the base of the petiole, resembling a small leaf. Stipules may be lasting and not be shed (a stipulate leaf, such as in roses and beans), or be shed as the leaf expands, leaving a stipule scar on the twig (an exstipulate leaf). The situation, arrangement, and ...
Leaf of Pyrus calleryana with petiole. In botany, the petiole (/ ˈ p iː t i. oʊ l /) is the stalk that attaches the leaf blade to the stem. [1]: 87 [2]: 171 It is able to twist the leaf to face the sun, producing a characteristic foliage arrangement (spacing of blades), and also optimizing its exposure to sunlight.
In the case of ferns, the stipe is only the petiole from the rootstock to the beginning of the leaf tissue, or lamina. The continuation of the structure within the lamina is then termed a rachis. In flowering plants, the term is often used in reference to a stalk that sometimes supports a flower's ovary.
Acrodromous – the veins run parallel to the leaf edge and fuse at the leaf tip. Actinodromous – the main veins of a leaf radiate from the tip of the petiole. Brochidodromous – the veins turn away from the leaf edge to join the next higher vein. Campylodromous – secondary veins diverge at the base of the lamina and rejoin at the tip.
Prickles on a blackberry branch. In plant morphology, thorns, spines, and prickles, and in general spinose structures (sometimes called spinose teeth or spinose apical processes), are hard, rigid extensions or modifications of leaves, roots, stems, or buds with sharp, stiff ends, and generally serve the same function: physically defending plants against herbivory.
They always have stipules, which can be leaf-like (e.g. Pisum), thornlike (e.g. Robinia) or be rather inconspicuous. Leaf margins are entire or, occasionally, serrate. Both the leaves and the leaflets often have wrinkled pulvini to permit nastic movements. In some species, leaflets have evolved into tendrils (e.g. Vicia). [3] [9] [18]