The San Diego State University Herbarium (SDSU) is a depository of over 26,000 pressed and mounted specimens of vascular plants and over 400 specimens of algae, used in research and teaching. We have also initiated a bryophyte and lichen collection. The purpose of these specimens is: 1) to serve as voucher documentation for research projects; 2) to serve as resources for plant identification; and 3) to serve as exemplars in plant courses. In addition, the herbarium both receives and provides loans of plant specimens used in active systematic research. The herbarium collection specializes in land plant specimens from San Diego County, California, and Baja California, with some collections from Australia, Chile, and the south Pacific.