BOTANY

the branch of biology that deals with plants. It involves the study of the structure, properties, and biochemical processes of all forms of plant life, including trees. Also included within its scope are plant classification and the study of plant diseases and of the interactions of plants with their physical environment. Over the years various specialized branches of botany have developed, and the principles and findings of botany, moreover, have provided the base on which depend such applied plant sciences as agriculture, horticulture, and forestry. The science of botany traces back to the ancient Greco-Roman world but received its modern impetus in Europe in the 16th century, mainly through the work of various physicians and herbalists. These professionals, in seeking plants useful in medicine, began seriously to observe plants themselves, as reflected in the woodcuts with which their herbal books were illustrated. In the 17th century, as a result of the earlier revival of learning and of increased facilities for travel and study in Europe and Asia, many more plants became known, and some botanists turned from medical botany to attempts to name and catalog all known kinds of plants. The most celebrated early work of this kind was Pinax theatri botanici (1623; Illustrated Exposition of Plants) by the Swiss scientist Gaspard Bauhin, who listed and described about 6,000 species. In the 18th century the greatest figure in botany was the Swedish scientist Carolus Linnaeus. His most valuable and lasting contributions were his careful descriptions of approximately 6,000 species arranged in genera (the same arrangement used today), his collation of the species that he knew with the names and descriptions of previous botanists, and his rules of nomenclature. He established binomial nomenclaturei.e., the naming of each species by two words, of which the first is the name of the genus to which it belongs and the second is a qualifying word, usually an adjective (e.g., the dog rose is Rosa canina). Even in this early period, botany was becoming specialized. While many botanists were occupied only with the classes and names of plants, the foundations of anatomy, morphology, and physiology were being laid. The important field of genetics was initiated in the 19th century, principally through the work of the Austrian botanist Gregor Mendel. Today the principal branches of botanical study are morphology, physiology, ecology, and systematics (the identification and ranking of all plants). Various subdisciplines include bryology (the study of mosses and liverworts), pteridology (the study of ferns and their relatives), paleobotany (the study of fossil plants), and palynology (the study of modern and fossil pollen and spores). branch of biology that deals with the study of plants, including their structure, properties, and biochemical processes. Also included are plant classification and the study of plant diseases and of interactions with the environment. The principles and findings of botany have provided the base for such applied sciences as agriculture, horticulture, and forestry. Plants were of paramount importance to early man; he depended upon them as sources of food, shelter, clothing, medicine, ornament, tools, and magic. Today it is known that, in addition to their practical and economic values, green plants are indispensable to all life on Earth: through the process of photosynthesis, plants transform energy from the sun into the chemical energy of food, which makes all life possible. A second unique and important capacity of green plants is the formation and release of oxygen as a by-product of photosynthesis. The oxygen of the atmosphere, so absolutely essential to many forms of life, represents the accumulation of over 3,500,000,000 years of photosynthesis by green plants. Although the many steps in the process of photosynthesis have become fully understood only in recent years, even in prehistoric times man somehow recognized intuitively that some important relation existed between the sun and plants. Such recognition is suggested by the fact that, in primitive tribes and early civilizations, worship of the sun was often combined with the worship of plants. Earliest man, like the other anthropoid mammals (e.g., apes, monkeys), depended totally upon the natural resources of his environment, which, until he developed methods for hunting, consisted almost completely of plants. The behaviour of pre-Stone Age man can be inferred by studying the botany of aboriginal peoples in various parts of the world. Isolated tribal groups in South America, Africa, and New Guinea, for example, have extensive knowledge about plants and distinguish hundreds of kinds according to their utility, as edible, poisonous, or otherwise important in their culture. They have developed surprisingly sophisticated systems of nomenclature and classification, which approximate the binomial system (i.e., generic and specific names) found in modern biology. The urge to recognize different kinds of plants and to give them names thus seems to be as old as the human race. In time plants were not only collected by primitive man but also grown by him. This domestication resulted not only in the development of agriculture but also in a greater stability of human populations that had previously been nomadic. From the settling down of agricultural peoples in places where they could depend upon adequate food supplies came the first villages and the earliest civilizations. Because of the long preoccupation of man with plants, a large body of folklore, general information, and actual scientific data has accumulated, which has become the basis for the science of botany. Additional reading Specific references on botany include Merritt Lyndon Fernald, Gray's Manual of Botany, 8th ed. (1950, reprinted 1988), taxonomic references for more than 8,000 species of plants found in North America; Arthur W. Galston, Peter J. Davies, and Ruth L. Satter, The Life of the Green Plant, 3rd ed. (1980), a well-organized and interesting presentation of functional botany; Michael Crawley (ed.), Plant Ecology (1986), a discussion of factors that influence the distribution and abundance of plants; David K. Northington and J.R. Goodin, The Botanical World (1984), an overview of plant morphology, physiology, and role within an ecosystem; Donna N. Schumann, Living with Plants: A Gardener's Guide to Practical Botany, 2nd ed. (1992); Kingsley R. Stern, Introductory Plant Biology, 6th ed. (1994), basic information on plant structure, function, reproduction, and evolution; James D. Mauseth, Botany: An Introduction to Plant Biology (1991), and Plant Anatomy (1988), an integration of plant structure and function; Lincoln Taiz and Eduardo Zeiger (eds.), Plant Physiology (1991), essays summarizing important principles; R.P.F. Gregory, Biochemistry of Photosynthesis, 3rd ed. (1989), covering the details of photosynthesis; G. Robin South and Alan Whittick, Introduction to Phycology (1987), a systems approach to the study of algae, profusely illustrated; Susan Isaac, Fungal-Plant Interactions (1992), a synthesis of fungal physiology, plant pathology, and biology; M.M. Yeoman (ed.), Plant Cell Culture Technology (1986), a discussion of the application of plant cell and tissue cultures in industry; and S.H. Mantell, J.A. Matthews, and R.A. McKee, Principles of Plant Biotechnology (1985), relating the principles to crop improvement and to the use of natural plant processes in industry. Michael J. Pelczar, Jr. Rita M. Pelczar The Editors of the Encyclopdia Britannica