Schimper, Karl Friedric (shĭmˈpər) [key], 1803–67, German botanist. He did important work in plant morphology and originated the theory, called phyllotaxis, that there is a fixed order to the arrangement of leaves on plant stems. His grandson, Andreas Franz Wilhelm Schimper, 1856–1901, wrote on plant ecology, gathering materials for his works in North America, Asia, and the West Indies as well as in Europe. In 1898 he prepared the first map of plant distribution. Among his work is Plant-Geography upon a Physiological Basis (1898, tr. 1903).