A herbarium is a museum for plants. The collection data associated with plant specimens enable then to provide a detailed record of the plants that occur or occurred in a particular area. For example, herbarium specimens provide a record of plants that occurred in the Tucson basin when the population was only a tiny fraction of what it is today, and lots of plants that grew in and along the Santa Cruz River when it flowed year round.
Students use the herbarium for class projects and for research related to plants.
Arizona Poison Control uses the herbarium to identify plants in cases of suspected poisoning. Horticulturists use the herbarium to identify plants that grow well in gardens and to search for related plants that might do as well. Homeowners use the herbarium to identify weeds as well as desirable plants in their backyards, for advice on what species to plant, and for help in identifying rare plants.