Located in Holt Hall room 129, the Herbarium is the most complete repository of plant specimens from northeastern California. The emphasis is on the northern California flora, and includes a great number of rare, threatened, and endangered plant species. Established with specimens donated by the late Professor Vesta Holt in the 1950's, the herbarium now contains more than 105,000 dried and mounted plant specimens. The majority of samples are flowering plants, conifers, and ferns, but bryophytes, lichens, and especially slime molds, are also well represented. The herbarium is used extensively for identification of sensitive and other plant species by various agencies and individuals. Loans of herbarium specimens are made to any higher academic institutions who request them.