Hardwoods
Hardwoods
trees and shrubs, mostly with lamelliform leaves that are distinguished by reticulate venation and more or less clearly defined petioles. Hardwoods belong to the division of angiosperms, and originated later than the conifers (which belong to the division of gymnosperms). They differ from conifers in that they have an ovary which, after fertilization, turns into a fruit (the conifers form seeds). Their wood consists of a variety of elements, whereas the wood of conifers only has tracheids. Hardwoods are divided into those with hard wood (oak, beech, hornbeam, ash, maple, and saxaul) and those with soft wood (birch, aspen, alder, linden, and poplar).
Some species, such as linden and filbert, demand good soils; others, such as birch and black locust, are relatively undemanding. Distinctions are made between hardwoods that are frost resistant (birch and aspen) and thermophilic (apricot, smoke tree, and honey locust), between those that require light and grow rapidly (birch and poplar) and those that tolerate shade but grow slowly (linden and hornbeam), between those with long life-spans (oak and beech) and those with short life-spans (aspen and poplar), and between those that are drought resistant (saxaul, pistachio, and oleaster) and those that are salt tolerant (honey locust, saxaul, and sumac). These trees and shrubs propagate from seeds and vegetatively.
Hardwoods are grown for their wood, as shelterbelts, for stabilizing soils, and for landscaping. They yield industrial raw materials (spindle tree, eucommia, oak, and privet) and various food products, including fruits (quince and filbert), honey (linden, acacia, and willow), spices (laurel and kochia), and medicinal preparations (viburnum, birch, honeysuckle, linden, and sea buckthorn).
IU. D. ISHIN and N. B. ISHINA