The binomial system of classification
Whilst Carl Linnaeus was Professor of Botany in Uppsala, he became aware of the limitations of the plant naming system. The names were based on the physical characteristics of the plants and were long and unwieldy.
Linnaeus came up with a beautiful simple two-part naming system. The first part of the name indicated the group to which the particular plant belonged (now known as the genus), and the second part indicated the species. He published a book naming over 7,700 species using this binomial system.