There are some trees that multiply asexually, i.e. by vegetative means. In one such example, root stickers, new individuals grow from the roots of the parent tree, which may soon be surrounded by a whole group of young trees. This means of reproduction is found in the aspen, white poplar, black locust, wild cherry, etc.
The seed is made up of a membranous or hard outer covering - the seed coat or testa - and the inner nucleus, which contains only the embryo and food reserves for the initial period of growth stored in the seed leaves (cotyledons) of the embryo (oak, beech, horse-chestnut, maple, ash, etc.). Some seeds contain a separate food reserve (endosperm) which surrounds the embryo and provides food for its growth (many conifers, etc.). Often clearly discernible on the seed is the scar where it was attached to the fruit. Usually this is light in colour (horse- chestnut and many Leguminosae). When germinating, it is through this scar that the seed absorbs the most water and through or near it that the first root and shoot emerge.
The tallest and largest trees are the sequoias of North America (Sequoiadendron giganteum Buchh. and Sequoia sempervirens Endl.), the latter attaining heights of up to 112 metres or more. Heights of 80 to 90 metres are reached by some other west American conifers, e.g. the giant fir, noble fir, Douglas fir and sugar pine. Of the European trees the tallest is the European silver fir with a height of over 62 metres and the Norway spruce, which also attains a height of over 60 metres.
Conifers generally lack it altogether, and in early youth it is found only in the yew, eastern arbor-vitae and some cypresses. Almost all broad-leaved trees exhibit this ability in youth, but later, after the age of maturity, it disappears in of trees with a constant ability to produce suckers in great abundance includes the willow, poplar, lime, hornbeam, alder, black locust, elm and oak, those with a moderate output include the maple, ash and mountain ash.
If conditions are favourable, the seeds of most woody plants germinate within three to four weeks of sowing. But in some trees the period of germination is longer when sown in spring. If the seeds have become too dry during the winter storage they may not germinate at all, or else not until the following Npring. This is true of many seeds, particularly of large seeds or those that fall from the tree in the autumn (silver fir, Douglas lir, white pine, common yew, oak, beech, chestnut, maple, etc.).
Since the annual growth begins early in spring, usually before the tree's assimilation organs are fully developed, the substances required are taken from the previous year's store; the extent of growth is thus mainly influenced by the weather of the preceding year. - 15266
The seed is made up of a membranous or hard outer covering - the seed coat or testa - and the inner nucleus, which contains only the embryo and food reserves for the initial period of growth stored in the seed leaves (cotyledons) of the embryo (oak, beech, horse-chestnut, maple, ash, etc.). Some seeds contain a separate food reserve (endosperm) which surrounds the embryo and provides food for its growth (many conifers, etc.). Often clearly discernible on the seed is the scar where it was attached to the fruit. Usually this is light in colour (horse- chestnut and many Leguminosae). When germinating, it is through this scar that the seed absorbs the most water and through or near it that the first root and shoot emerge.
The tallest and largest trees are the sequoias of North America (Sequoiadendron giganteum Buchh. and Sequoia sempervirens Endl.), the latter attaining heights of up to 112 metres or more. Heights of 80 to 90 metres are reached by some other west American conifers, e.g. the giant fir, noble fir, Douglas fir and sugar pine. Of the European trees the tallest is the European silver fir with a height of over 62 metres and the Norway spruce, which also attains a height of over 60 metres.
Conifers generally lack it altogether, and in early youth it is found only in the yew, eastern arbor-vitae and some cypresses. Almost all broad-leaved trees exhibit this ability in youth, but later, after the age of maturity, it disappears in of trees with a constant ability to produce suckers in great abundance includes the willow, poplar, lime, hornbeam, alder, black locust, elm and oak, those with a moderate output include the maple, ash and mountain ash.
If conditions are favourable, the seeds of most woody plants germinate within three to four weeks of sowing. But in some trees the period of germination is longer when sown in spring. If the seeds have become too dry during the winter storage they may not germinate at all, or else not until the following Npring. This is true of many seeds, particularly of large seeds or those that fall from the tree in the autumn (silver fir, Douglas lir, white pine, common yew, oak, beech, chestnut, maple, etc.).
Since the annual growth begins early in spring, usually before the tree's assimilation organs are fully developed, the substances required are taken from the previous year's store; the extent of growth is thus mainly influenced by the weather of the preceding year. - 15266
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When you plan your garden, keep in mind the rough positioning of the main functional areas, mark in the broad sweep of the garden design.
