A herbarium is a collection of preserved plants stored, catalogued, and arranged systematically for study by professionals and amateurs from many walks of life. A collection like this is a vital reference when you need to identify a plant and also serves to fix forever the identity of thousands of plant names.

In addition to their taxonomic import, herbaria are commonly used in the fields of ecology, plant anatomy and morphology, conservation biology, biogeography, ethnobotany, and paleobotany. The sheets provide biogeographic information that can be used to document the historic ranges of plants, to locate rare or endangered species, or to trace the expeditions of explorers and plant collectors. Physically, the specimens are important sources of genetic material for DNA analyses and of pollen for palynological studies. Herbarium sheets are often shared among researchers worldwide, and the specimens of many herbaria have been digitized to further facilitate their use.