The De Candolle system is a system of plant taxonomy by French (Swiss) botanist Augustin Pyramus de Candolle (1778−1841).
The first taxonomic system by de Candolle, who introduced the term taxonomy, appeared in his description of the plants of France, his Flore française (1805–1815), in 5 volumes dealing with plant species found in France.
The De Candolle system is a subsequent taxonomic system.
The abbreviation Syst. in de Candolle's work and subsequent literature refers to his Regni vegetabilis systema naturale.
The De Candolle system recognises the following groups of vascular plants (references to Prodromus). Within the Prodromus he cross references his earlier Regni vegetabilis systema naturale.
A general schema is laid out in the Regnii vegetabilis pp. 117–122, as follows:
Plantae Vasculares seu Cotyledoneae DC.
11 families
Vol IV - 2 parts Vol V
List of De Candolle system families recognized in the Théorie élémentaire de la botanique (1813), on page 213:
The De Candolle system families were further developed in the Prodromus (1824–1873).
Note that this system was published well before there were internationally accepted rules for botanical nomenclature. Here, a family is indicated as "ordo". Terminations for families were not what they are now. Neither of these phenomena is a problem from a nomenclatural perspective, the present day ICBN provides for this.
Within the dicotyledons ("classis prima DICOTYLEDONEÆ") the De Candolle system recognises (Pagination from Prodromus, 17 Parts) the list:
(Index to Part I p. 741)
Somewhat inconsistently the Prodromus also treats:
(Overall Index Part XVII Page 323)