Candolle, Augustin Pyrame de

▪ Swiss botanist

born Feb. 4, 1778, Geneva

died Sept. 9, 1841, Geneva

 Swiss botanist who established scientific structural criteria for determining natural relations among plant genera. After Charles Darwin's introduction of the principles of organic evolution, Candolle's criteria provided the empirical foundation for a modern evolutionary history of plants. His system of plant classification found nearly universal application for half a century, during which time it served as a model for other systems.

      After his arrival in Paris (1796), Candolle struck up a friendship with the French naturalists Georges Cuvier and Jean-Baptiste de Lamarck, became an assistant to Cuvier at the Collège de France (1802), and prepared revisions of Lamarck's Flore française (1805, 1815). When he was appointed professor of botany at the University of Montpellier (1808), Candolle had already begun a government-commissioned botanical and agricultural survey of France (1806–12), the results of which he published in 1813.

      Also in 1813 Candolle published his most important work, Théorie élémentaire de la botanique, in which he contended that plant anatomy, not physiology, must be the sole basis of classification, for which he coined the term taxonomy. After introducing the concept of homologous parts (of common ancestry, although different in structure) for plants as Cuvier had done for animals—particularly convincing evidence in favour of organic evolution—Candolle, like Cuvier, nonetheless retained a firm belief in the constancy of species.

      Accepting the natural history chair at the Université de Genève (1817–41), where he was the first director of the botanical gardens, Candolle undertook the detailed development of ideas presented in the Théorie, first outlining systematic laws of botanical nomenclature in his Regni Vegetabilis Systema Naturale (2 vol., 1818–21; “Natural Classification for the Plant Kingdom”). He next undertook the most ambitious task of preparing a descriptive classification of all known seed plants, Prodromus Systematis Naturalis Regni Vegetabilis (17 vol., 1824–73), for which he prepared the first seven volumes.

      Although his taxonomy suffered from a failure to observe his own criteria in formulating broad taxa, resulting in his inclusion of gymnosperms with dicotyledons, ferns with monocotyledons, and all else as acotyledons, Candolle achieved extensive subdivision of flowering plants, describing 161 families of dicotyledons, and demonstrated decisively the inadequacy of Linnaean classification, which his system supplanted. He also pioneered the study of phytogeography, the biogeography of plants, by carrying out investigations in Brazil (1827), East India (1829), and North China (1834).

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