The herbarium of the California Academy of Sciences (CAS) is the largest collection of vascular plants in the western U.S. It is the sixth largest collection in the United States. Together with the Herbarium of the University of California at Berkeley (UC) the San Francisco Bay area is regarded as a National Resource Center for systematic botany. These two major collections have an informal agreement to avoid duplication, thus providing botanists with a rich and varied resource for research.


The CAS 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 more than 11,000 types (holotypes, isotypes, syntypes, lectotypes, and neotypes) housed separately from the general collection.


The collection was built largely as the result of research collections by the curators and staff of CAS and the Dudley Herbarium (DS) and augmented by purchases, exchanges, and bequests made over the years. The collection is strongest in vascular plants from North and Latin America (particularly California and western and southern Mexico) and the Galapagos Islands, as well as important collections from other areas of the world. Some vascular plant families and genera that are especially well represented are Acanthaceae, Brassicaceae, Carex, Eriogonum, Hydrophyllaceae, Lupinus, Madinae (Asteraceae), Malvaceae, Melastomataceae, Onagraceae, Penstemon, Poaceae, Polemoniaceae, and Quercus. The herbarium also includes the largest collection of ornamental plants in California.


The main focus for growth presently involves the acquisition of plants from Latin America (particularly Mexico, Central America, and northern South America), Eastern Asia (particularly China), and Western North America (particularly California, Nevada, and Arizona).


Herbarium specimens are mounted on 100% rag paper, with locality data, collector information and determination printed on a label affixed at the lower right corner of the sheet.

Department of Botany History

The Botany Department was founded as part of the California Academy of Natural Sciences in 1853. The early herbarium (now CAS) included specimens collected by Dr. Albert Kellogg, a medical practitioner and one of the founders of the Academy.

Terms of Use

These databases and all images within them are owned and copyrighted by the California Academy of Sciences, ©2009, or licensed to it.  The data and images may be used freely by individuals and organizations for purposes of basic research, education and conservation.  These data and images may not be used for commercial or for-profit purposes without the express written consent of the California Academy of Sciences, and may not be repackaged, resold, or redistributed in any form.

Use of the data or images in publications, dissertations and theses, or other scientific reports, should be accompanied by an acknowledgement of the Department of Botany, California Academy of Sciences, as the source for the information.  Please provide the Department with separates of articles resulting from the use of these data or images.  This helps us to document the use of specimens as “vouchers” in the literature.  It also helps us to justify continued funding for the collections so that these resources remain available into the future.

Search Collections



Quick tips on how to search the collections database:

 1. Our collections database is not case sensitive

 2. Use either an "*" or "%" as a wilcard



How to Search the Botany Collection

Please note: as of March 21, 2013 our database is currently undergoing maintenance.


Currently the Botany database contains records for about 140,000 of our specimens.  The following portions of our collection are included in the database: 1) our type collections; 2) all of our collections from Modoc County; 3) Dennis Breedlove's collections from Chiapas, Mexico; 4) records from Yunnan Province, China; 5) Ferns and gymnosperms fromt he Bay Area; 6) Packera (Asteraceae) records from California; 7) recent curator collections from Latin American, Madagascar, and Sabah.  We are currently adding; 8) California Cyperaceae; and 9) California Delphinium species.  In the near future we will be adding additional California records.


If you are searching for these records and are having trouble finding what you need, try limiting your search to as little information as possible (e.g., ONLY genus and species or only family).

Contact the Collections Manager

For inquiries please contact:

  • Debra Trock
  • Senior Collections Manager
  • California Academy of Sciences
  • 55 Music Concourse Drive
  • San Francisco, CA 94118
  • 415-379-5363 (direct)

Contact the Department

  • Botany Administrator
  • California Academy of Sciences
  • 55 Music Concourse Drive
  • San Francisco, CA 94118
  • 415-379-5361 (direct)