The OSU Herbarium contains approximately 157,000 vascular plant specimens, about two-thirds of which were collected in Oklahoma and surrounding states. The oldest specimen dates from 1843, and the collection contains 300 type specimens. Since its establishment in 1920, it has been curated by Henry Ira Featherly (1925-1937), Robert Stratton (1937-1949), Umalde Theodore (“Ted”) Waterfall (1949-1971), and Ronald Tyrl (1972-2008). Since 2009, Mark Fishbein has been the herbarium director. The herbarium houses a seed/fruit collection, cryptogamic collection, and botanical library.