The Marion Ownbey Herbarium (WS) is a collection of over 430,000 specimens of vascular plants, bryophytes, and lichens.  The herbarium includes plants from around the world, with an emphasis on species from eastern Washington, Idaho, and Oregon, as well as the northern Rocky Mountains, Great Basin, California, and western Canada.  WS is especially strong in collections of Allium, Carex, Castilleja, Eriogonum, Lomatium, Lupinus, Mentzelia, Penstemon, Synthyris, Tillandsia, and Tragopogon.  Prominent collectors from the herbarium include Wilhelm Suksdorf, C.V. Piper, Harold St. John, Marion Ownbey, C.L. Hitchcock, Arthur Cronquist, Rex Daubenmire, Robert Whittaker, and Noe & Betty Higinbotham.