The leaf blade is patterned with veins. The leaves of most woody plants have one principal vein with several branching veins extending to the leaf margin. Some perennial plants, usually those with palmately lobed leaves, have palmate venation with several veins of like thickness radiating from the end of the rachis (e.g. gooseberry).
Distinguishing features of the leaf are the overall shape, the margin, the arrangement on the twig, the venation (vein pattern), and in some cases also the hairiness of the surface. According to their arrangement leaves arc either alternate, where only a single leaf is attached at each node on the twig and the leaves are usually arranged in spirals, as in the hazel, hawthorn and barberry, or opposite, with leaves paired at the same point, one on each side of the twig, e.g. the dogwood, spindle tree, lilac and ash.
The leaves likewise serve as an organ of transpiration, excess water absorbed by the roots being passed back to the atmosphere from the leaf surface in the form of vapour after the plant has extracted the mineral substances contained therein.
This is caused by the decomposition of the green chlorophyll, the predominance of yellow xanthophyll and red carotenoid pigments and increased level of anthocyanin in the cell plasm. Autumn coloration is likewise a distinguishing feature in a number of shrubs.
The placing of the leaves in the crown likewise contributes to the better utilization of light. This is aided by the intricate branching of the crown as well as by the varying length and angle of the leaf stalks. Respiration and transpiration take place through pores or stomata.
Leaf margins are smooth and entire (e.g. the common cotoneaster, woodbine, cornelian cherry and dogwood), serrate (the common elder, blackthorn and rose), double serrate (the hazel, European green alder and raspberry), toothed (the English holly and mahonia) or lobed (the hawthorn and currant).
Distinguishing features of the leaf are the overall shape, the margin, the arrangement on the twig, the venation (vein pattern), and in some cases also the hairiness of the surface. According to their arrangement leaves arc either alternate, where only a single leaf is attached at each node on the twig and the leaves are usually arranged in spirals, as in the hazel, hawthorn and barberry, or opposite, with leaves paired at the same point, one on each side of the twig, e.g. the dogwood, spindle tree, lilac and ash.
The leaves likewise serve as an organ of transpiration, excess water absorbed by the roots being passed back to the atmosphere from the leaf surface in the form of vapour after the plant has extracted the mineral substances contained therein.
This is caused by the decomposition of the green chlorophyll, the predominance of yellow xanthophyll and red carotenoid pigments and increased level of anthocyanin in the cell plasm. Autumn coloration is likewise a distinguishing feature in a number of shrubs.
The placing of the leaves in the crown likewise contributes to the better utilization of light. This is aided by the intricate branching of the crown as well as by the varying length and angle of the leaf stalks. Respiration and transpiration take place through pores or stomata.
Leaf margins are smooth and entire (e.g. the common cotoneaster, woodbine, cornelian cherry and dogwood), serrate (the common elder, blackthorn and rose), double serrate (the hazel, European green alder and raspberry), toothed (the English holly and mahonia) or lobed (the hawthorn and currant).
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The variety of garden materials present a futher range of garden design in your garden plan, involving color and texture as well as linear design.
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