Candolle, Augustin de

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Candolle, Augustin de

Swiss Botanist
1778-1841

Augustin de Candolle was a Swiss botanist who advanced significant ideas concerning the classification of plants and developed a taxonomic scheme that provided the foundation for much work in taxonomy up to the present.

As did most learned men of science in his day, Candolle trained in medicine, earning a medical degree from the University of Paris in 1804. During this time, he became friends with several other scientific luminaries working in Paris, including the evolutionary theorist Jean-Baptiste Lamarck (1744-1829) and the paleontologist Georges Cuvier (1769-1832). Candolle became an assistant to Cuvier for a time and helped to revise Lamarck's treatise on French flora.

By this time, Candolle had become professionally interested in botany, and in 1806 obtained a commission to conduct a botanical and agricultural survey of France, an endeavor conducted over the next six years. In 1808 he was appointed professor of botany at the University of Montpellier, where he began work on his Théorie Élémentaire de la Botanique (Elementary Theory of Botany), published in 1813.

In this work, Candolle laid out his most significant intellectual contribution to plant taxonomy (and in fact coined the word "taxonomy" as well). Candolle believed that a natural classification scheme should be based on the anatomic characteristics of plants, and in particular the positional relations among parts. Candolle argued, for instance, that in the flower, the position of the stamens in relation to the petals provides important information about whether two species are closely or more distantly related: the more similar the arrangement of parts, the more likely the two species are closely related. While strong adaptational pressures might cause two close relatives to diverge in shape, color, or size, the relation of parts—what Candolle called "symmetry"—would not be as likely to change, since these relations reflected a developmental program that would be much more resistant to large evolutionary changes in a short time. While modern taxonomists use other criteria besides those Candolle proposed, his essential insight into the significance of positional relationships remains an important part of the taxonomist's toolbox.

Candolle became professor of natural history at the University of Geneva in 1817, where he remained until his death. He was the first director of the botanical gardens there, and established what is now one of the world's largest herbarium. He expanded on his theories of classification in Regni vegetabilis systema naturale (Natural Classification for the Plant Kingdom), published in 1818, and began the most ambitious task of his life, the Prodromus systematis naturalis regni vegetabilis, intended to be a descriptive classification of all known seed plants. Candolle's goal was not only to classify every known species, but also to include ecology, evolution, and the biogeography of each (Candolle was, in fact, a pioneer in the field of biogeography). Candolle died in 1841 having completed only seven volumes, but the work was carried on by his son, Alphonse de Candolle (1806-1893), and eventually reached seventeen volumes.

Hundreds of individual plant species were first described and named by Augustin de Candolle, including purple coneflower (Echinacea angustifolia ), the source of the popular herbal remedy echinacea. Genetic studies of Arabidopsis have borne out Candolle's belief that positional relationships are deeply embedded in the genetic program. His son Alphonse, in addition to completing the Prodromus, was a leading botanist in his own right. Candolle the younger made major contributions to the theory of the origin of cultivated plants, laying out ideas taken up and expanded upon by Russian geneticist N. I. Vavilov (1887-1943), and published an important early work on plant biogeography.

see also Arabidopsis; Biogeography; Herbaria; Taxonomist; Taxonomy; Taxonomy, History of; Vavilov, N. I.

Richard Robinson