The OSU Herbarium contains approximately 140,000 specimens, largely from Oklahoma and surrounding states. The oldest specimen dates from 1862, and there are 215 types. Since its establishment in 1920, it has been curated by R. Stratton, H. I. Featherly, and U. T. Waterfall. Its current curator is Ronald Tyrl, a specialist in grasses and the flora of Oklahoma. The herbarium also houses a seed/fruit collection, a cryptogamic collection, library of botanical books, and a complete set of topographical maps of the State of Oklahoma.