Botany, also called plant science(s) or plant biology, is a discipline of biology and the science of plant life. The term "botany" is derived from the Ancient Greek word βοτάνη (botane) meaning "pasture", "grass", or "fodder"; βοτάνη is in turn derived from βόσκειν (boskein), "to feed" or "to graze". A person engaged in the study of botany may be called a botanist or a plant scientist. Nowadays, botanists study approximately 400,000 species of living organismsof which some 260,000 species are vascular plants and about 248,000 are flowering plants. Botany is the scientific study of plants. "Plants," to most people, means a wide range of living organisms from the smallest bacteria to the largest living things - the giant sequoia trees.