Candolle, Augustin Pyrame de (1778-1841), a Swiss botanist, published many books about plant classification and its theoretical aspects. His Theorie Elementaire de la Botanique (1813), Regni Vegetabilis Systema Naturale (1817-1821), and Prodromus Systematis Naturalis Regni Vegetabilis (begun in 1824) laid the foundations for modern studies on plant evolution and classification. De Candolle was born in Geneva.