The Herbarium at SOU (Herbarium code SOC) is a collection of pressed plant specimens located in the Department of Biology Natural History Museum. It was begun by Dr. Frank Lang in 1967 as a teaching facility, it contains representatives of regional flora and serves as a repository for voucher specimens and as a secure site for loans from other institutions for local faculty and student researchers. This collection assists researchers land managers in providing evidence of the arrival of invasive species in an area and the shifting of species ranges in response to climate change and identifying weeds and rare species. Herbarium SOC collections have shown the occurrence in southern Oregon of species formerly known only from California. Information and images for over 23,000 SOC specimens are listed in the database of the Consortium of Pacific Northwest Herbaria, with about 3000 specimens not yet entered. About 21,000 specimens are from Oregon, almost 10,000 from Jackson County, and 1650 from California. The majority of specimens were collected by SOU students. The Herbarium includes gifts from Oregon State University, the University of Oregon, the Rogue River-Siskiyou National Forest, old collections formerly held by the Klamath Falls Museum, and private collections from Jim Duncan, Frank Callahan, and other botanists.