Irises are classed in two ways Botanical Classification and Horticultural Classification. Botanical classification tries to sort plants to show evolutionary relationships. Horticultural classification sorts plants by their roles in the garden. The evolutionary tree that is developed by botanical classification is called phylogeny.
Modern taxonomy now relies on cladistics to understand evolution but it is hard to escape the traditional categories known as taxa. A good way to trace the phylogeny of the Iris in this wiki is to start at the Genus Iris and follow the links downward through progressively lower taxa, to the level of species.
While no species requires all rankings the order of ranks of taxa below the rank of Genus is:
Below the species level we have the descending ranks:
Starting at the Plant Kingdom the rankings work downward to the genus Iris in this way:
As needed any rank can have a sub or super rank. Each of these categories singley is called a taxon and the enumeration of the taxa, is taxonomy. Taxonomy has traditionally been based on the physical morphology of the plant. The new experimental approaches to studying phylogeny are termed systematics. A new approach to studying the phylogentic tree is called cladistics, named after clades, the branches of the tree (clade=branch).
As our knowledge increases the way the species are sorted into the various taxa changes. The first comprehensive monograph was in 1914 by William Rikatson Dykes. Later various authors have attempted to update or revise this treatment; To see the views of other taxonomists click on the following names;
-- Main.RPries - 2010-02-04