California Academy of Sciences Botany Collection, San Francisco (CAS-Botany)
The herbarium of the California Academy of Sciences is the largest collection of vascular plants in the western U.S. It is the sixth largest collection in the United States. The Academy collection includes approximately 2 million plant specimens. More than 95% of the specimens are vascular seed plants; the remainder are ferns and a growing collection of bryophytes. There are almost 12,000 types (holotypes, isotypes, syntypes, lectotypes, and neotypes) housed separately from the general collection.