The composition of a genus is determined by a taxonomist. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful:
The term comes from the Latin genus ("origin; type; group; race"), a noun form cognate with gignere ("to bear; to give birth to"). Linnaeus popularized its use in his 1753 Species Plantarum, but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera".