Infageneric ranks in botany

[Kevin Thiele]

Does anyone know when infrageneric ranks (subgenera, sections, subsections,
series, subseries etc) were first used in botany?



Linnaeus originally had only 5 ranks (variety, species, genus, order~family
and class). By the middle of the 19th Century sections and series seem to
have been used fairly regularly.



So, who started this trend? And are there any definitive statements in the
early literature as to why they were introduced - two possible reasons are,
to reduce the number of included species in a group for mnemonic purposes,
and to reflect a growing understanding of natural groupings.



Cheers - Kevin Thiele