This is the famous Iris Data used by Fisher (1936)
Data found in Appendix B.2, page 445 of Morrison, D.F. (2005) Multivariate Statistical Methods, 4ed. Belmont, CA: Brooks/Cole Thomson Learning
They obtained it from -- Fisher, R.A. (1936) The use of multiple measurements in taxonomic problems, Annals of Eugenics 7: 179--188.
Who in turn obtained it from -- Anderson, E. (1935) The irises of the Gaspe Peninsula, Bulletin of the American Iris Society 59: 2--5.