Botany, in its general sense, signifies the knowledge of plants. In the earlier periods of human history plants appealed to mankind as material for food or medicine; and down to comparatively recent times botanical studies were pursued mainly in these directions. Dioscorides, a Greek, who lived in the first century of the Christian era, is the earliest writer of whom we have knowledge that can lay a claim to botanical distinction, but the medical property of plants was evidently the chief incentive to his task. It was not until the beginning of the sixteenth century that botany, in its broad sense, became a study, and Le Cluse, a French physician, who died in 1609, may be regarded as one of its patriarchs. Still the medical uses of plants were steadily kept in view. The English botanist, John Gerarde, who was a contemporary of Le Cluse, or Clusius, as botanists usually call him, wrote a remarkable work on botany,—remarkable for his time,—but this was styled a “Herbal,” as were other famous botanical works down to the beginning of the present century. Following the year 1700, the knowledge of plants individually became so extended that systematic arrangement became desirable. The first real advance in this direction was made by Carl Von Linné, commonly known by its Latin form, Linnæus, a Swede, born in 1707, and whose talents for botanical acquirements seemed almost innate. In his twenty-third year he saw the need of a better system, and commenced at once the great work of botanical reform. He saw that plants with a certain number of stamens and pistils were correlated, and he founded classes and orders on them. Flowers with five stamens or six stamens would belong to his class pentandria or hexandria, respectively, and those with five pistils or six pistils pentagynia, or hexagynia, accordingly; and so on up to polyandria, or polygynia—many stamens or pistils—of which our common buttercup is an illustration. He further showed that two names only were all that is necessary to denote any plant, the generic name and its adjective, as, for instance, _Cornus alba_, the white Dogwood; and that the descriptions should be brief, covering only the essential points wherein one species of plant differed from another. This became known as the sexual system. It fairly electrified intelligent circles. People generally took to counting stamens and pistils, and large numbers took pride in being botanists because they could trace so easily the classes and orders of the plants they met. The grand old man died in 1778, and though his artificial system had to give way to a more natural method, he is justly regarded as the father of modern botany. [Illustration: THE GREEN ROSE. Flower with leaves for petals.]