Trees and shrubs are perennial plants whose stems become woody and last for many years. Trees usually have a single erect stem or trunk which at a certain height branches out to form a crown, whereas shrubs branch from near to, or at, ground level.
Trees and shrubs are also differentiated according to height. Small trees attain, a height of about eight metres, those of the second category fifteen to twenty-four metres, and those of the first category more than twenty-five metres. The thickness of a tree is usually given by the diameter of the trunk measured at breast height, i.e. 1.3 metres above ground.
The forest provided primitive man with food, fuel and building material, affording him also protection against enemies and the elements. To realize the importance of trees and forests for man, however, there is no need to go so far back into the past. Even our great-grandfathers could say that trees and their wood were man's companions from birth to death - from wooden cradle to wooden coffin. Man used wood to build houses and make furniture, construct household utensils, tools and vehicles, and shape primitive weapons. Until almost the eighteenth century wood was also the only source of heat and energy.
A further good means of identification in some trees are the short, peg-like projections known as spurs (cherry, apple) on which the flower buds are borne. Some trees' twigs have distinctive large or small leaf scars which remain after the leaves falhe horseshoe-shaped ones of horse chestnut are noteworthy.
Spines and thorns are another good means of identification, e.g. on the twigs of the wild pear, black locust and honey locust. The twigs of other trees have conspicuous lenticels (bird-cherry, white ash), waxy warts (birches) or corky plates (hedge maple and smooth-leaved elm).
Under normal conditions trees are the strongest and fittest members of the plant realm.
Trees and shrubs are also differentiated according to height. Small trees attain, a height of about eight metres, those of the second category fifteen to twenty-four metres, and those of the first category more than twenty-five metres. The thickness of a tree is usually given by the diameter of the trunk measured at breast height, i.e. 1.3 metres above ground.
The forest provided primitive man with food, fuel and building material, affording him also protection against enemies and the elements. To realize the importance of trees and forests for man, however, there is no need to go so far back into the past. Even our great-grandfathers could say that trees and their wood were man's companions from birth to death - from wooden cradle to wooden coffin. Man used wood to build houses and make furniture, construct household utensils, tools and vehicles, and shape primitive weapons. Until almost the eighteenth century wood was also the only source of heat and energy.
A further good means of identification in some trees are the short, peg-like projections known as spurs (cherry, apple) on which the flower buds are borne. Some trees' twigs have distinctive large or small leaf scars which remain after the leaves falhe horseshoe-shaped ones of horse chestnut are noteworthy.
Spines and thorns are another good means of identification, e.g. on the twigs of the wild pear, black locust and honey locust. The twigs of other trees have conspicuous lenticels (bird-cherry, white ash), waxy warts (birches) or corky plates (hedge maple and smooth-leaved elm).
Under normal conditions trees are the strongest and fittest members of the plant realm.
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Garden planning of a garden for children should be designed to convert easily to a decorative layout.
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