Carl von Linné is considered the father of modern taxonomy. His binomial system of nomenclature was one of the first that really began to make sense to many people. Its organization based on the numbers of the sexual organs seemed to bring together plants that intuitively people felt were related. His seminal work Species Plantarum Vol. 1 p. 38 in 1753 is the baseline for our modern naming system.
Linnaeus knew only 17 species of Iris: