French botanist born into a family of plant enthusiasts, Antoine Laurent de Jussieu was based at the Jardin du Roi in Paris and was the seminal advocate of a natural system of classification. His uncle, Bernard de Jussieu was a respected botanist and invited the young Antoine to Paris as soon as he completed his preliminary studies in Lyons, his birthplace. Here A. L. Jussieu trained in medicine for four years. His uncle, a demonstrator at the Jardin du Roi, guided his studies and prepared him for a lecturer's position at the garden which was soon to become vacant.

At just 22 years old he gained the position and was charged with teaching morphology to his pupils using the plants in the garden which were arranged according to the artificial system of Joseph Pitton de Tournefort. His botanical training was quite limited because the subject was only viewed as an accessory to the medical course, so the inexperienced Jussieu had to study by night the topics he was due to teach the following day. It was not until 1773 that his true passion for botany and classification began, when, as part of an application for a place in the Academy of Sciences, he produced a treatment of the Ranunculaceae. Researching this group he developed his ideas on a system of classification for which he would later become famous.

Very soon it became apparent that the artificial system of Tournefort was inadequate and from 1774 Jussieu began arranging the plants in the Royal Garden in his own way. His ideas to create a new classification system were particularly inspired by those of Bernard de Jussieu, which he never published. The uncle did, however, create a catalogue of the plants in the garden of the Palace of Trianon, Versailles, which proved particularly useful to his nephew's work. For 19 years Antoine Jussieu laboured on the subject and finally published Genera plantarum segundum Ordines Naturales disposita in 1789. Although currently regarded as the forerunner to present day classification systems, Europe did not rapidly take to his ideas. Tournefort's system presided for many years in France and Iberia and in England and Germany the teachings of Carl Linnaeus were quickly adopted. Jussieu's ideas differed from that of the Swedish naturalist in that he used many characters but some were considered more important than others, depending on how variable they were within a species. Unlike Linnaeus' sexual system the characters were graded rather than counted and he put particular emphasis on the cotyledons and ovaries rather than the stamens.

In 1790 he was put in charge of the hospitals and charities of the city of Paris and when, in 1793, the garden's name was changed to the Jardin des Plantes Jussieu took on the role of professor of rural botany. These positions took up the majority of his time and during this period he stopped writing, never defending his theories against critics believing they did not need it. Later named director and treasurer of the Museum of Natural History he began to write again in 1802 and until 1820 published 15 papers treating some of his natural orders (now equivalent to families) in the Annales du Museum. Also during this period he undertook fieldwork in France, particularly on two occasions in 1812 with Sébastien Vaillant and Antoine-Tristan Danty d'Isnard. In the final years of his life Jussieu was almost blind as well as deaf but continued the religious practices which he had maintained throughout his life, meditating and in prayer. His son, Adrien, inherited his interest in botany and took over from him as botany lecturer at the garden, as well as proudly tending his father's manuscripts.

Sources:
C. Tomlinson, 1844, Linnaeus and Jussieu, or the rise and progress of systematic botany
E. Hawks, 1928, Pioneers of plant study.