[1] [2][3] He received his education in natural sciences at Geneva and Berlin,[4] and studied botany with Simon Schwendener, Adolf Engler, Marc Thury, Johannes Müller Argoviensis, and Alphonse de Candolle.
[1] In 1896 he became a curator at the Conservatoire Botanique, later serving as its director (1906–1931).
[4] Between 1895 and 1917, with Émile Burnat, he participated in a number of botanical trips, journeying to Corsica, Dalmatia, the Maritime Alps (France and Italy), Montenegro, et al.[4]
Besides his floristic work, he had a particular interest in the genus Galeopsis, and family Lamiaceae (Labiatae).
[1] He is especially remembered for his contributions to the "Rules of Nomenclature", the precursors of the modern International Code of Nomenclature for algae, fungi, and plants, with which he took a leading role from 1900, at a time when four sets of rules were competing for acceptance:[5]... for more than 30 years [he] was to take de Candolle's place as the leader in nomenclatural matters and ... by his clear-headedness, good nature, and judicial attitude was to contribute much to the solution of their problems.