botany, science devoted to the study of plants. Botany, microbiology, and zoology together compose the science of biology. Humanity's earliest concern with plants was with their practical uses, i.e., for fuel, clothing, shelter, and, particularly, food and drugs. The establishment of botany as an intellectual science came in classical times. In the 4th cent. B.C., Aristotle and his pupil Theophrastus worked out descriptions and principles of plant types and functions that remained the prototype for botanical observation for 1,000 years. During the stagnant period of the Middle Ages the knowledge of the classical scholars was preserved in the European monasteries and by the Arabs in the Middle East. In the 16th and 17th cent. an interest in botany revived in Europe and spread to America by way of European conquest and colonization. At that time both botany and the art of gardening (see garden) stressed the utility of plants for man; the popular herbal, describing the medical uses of plants, mingled current superstition with fact. In the late 17th and the 18th cent. the influence of the ancient scholars was modified by the growth of scientific botany. Through careful and accurate observation the sciences of taxonomy and morphology (see biology) were developed, providing the basis for the first systematic classification of organisms, chiefly in the work of Linnaeus. With the microscope came the development of plant anatomy and research on the cell. New knowledge of the principles of chemistry and physics spurred experimentation in plant physiology, notably the early work of Stephen Hales on the sources and manufacture of plant food, which led to studies of such basic processes as photosynthesis. Modern botany has expanded into all areas of biology, including molecular biology, and has developed such specialties as ethnobotany, which studies the use of plants in preindustrial societies. Perhaps most significant was the work of Mendel in plant breeding at the middle (1859) of the 19th cent., from which grew the science of genetics. Allied with experimental botany are the various practical aspects that have developed into specific scientific disciplines (e.g., agriculture, agronomy, horticulture, and forestry).