PPDC Botany lab banner

CDFA Herbarium (CDA)

3294 Meadowview Road
Sacramento, CA 95832
tel: 916-738-6706
fax: 916-262-1190

Curator:Dr. Genevieve Walden
email: genevieve.walden@cdfa.ca.gov
tel: 916-738-6688

For further information or loan requests, please contact the Curator.


The Botany lab was initially intended as a means of identifying current and potential weeds of agriculture. Its primary mission remains the identification of submitted specimens and first line assessment of their potential invasiveness. However, this role has expanded over the years as scientific understanding of the effects of invasive species on rangelands and native ecosystems has increased. Identifying and interpreting the behavior of agricultural weeds remains an important part of the Botany Lab's function, but identification of host plants for pathogens, insects and nematodes is a more recent emphasis, requiring an additional emphasis on horticultural and agricultural taxa. In addition wildland weeds, and even native species at risk are also evaluated as needed. The botany lab consults extensively with state agricultural officers and extension agents and the USDA, as well as NGOs such as the California Exotic Plant Pest Council (CalEPPC), the California native Plant Society (CNPS) to identify the most threatening plant invaders. Collaborations occur with California Department of Fish and Game (CDFG) and the Fish and Wildlife Service (USFWS) to assess the status and threats to native plant species.To all these ends Botany lab scientists collaborate with botanists around the world - they provide information and specimens as to identity, distribution, and behavior in the plants native or other introduced habitats.

History of the CDFA Herbarium:

In 1911 a cooperative USDA/State seed lab was founded in Berkeley. It moved to Sacramento in 1921, at which time the Herbarium (CDA) and Seed Laboratory were established. Although the collections are in close proximity, the Seed Herbarium was physically separated from the main Herbarium, forming a second, very significant collection. The total number of specimens in the plant Herbarium as of late 2007 is about 50,000. The Herbarium also maintains an extensive botanical library consisting of about 1500 volumes, and a searchable database of over 12,000 botanical and weed science articles available on the shelf or as reprints. In 1992 the Botany Lab and it's Herbarium moved to its current Meadowview Road facility, along with the rest of the Plant Pest Diagnostic Branch.

Botanists began with Margaret K. Bellue, who at that time identified both weeds and seeds. She was one of the co-authors for the original Robbins "Weeds of California" in 1941. Dr. Thomas C. Fuller followed in the late 1950s and retired in 1982. His book, "Poisonous Plants of California," published in collaboration with Elizabeth McClintock of the California Academy of Sciences, remains a significant reference work. Dr. G. Douglas Barbe worked with and trained under Tom Fuller for seven years, then was the sole botanist until his own retirement in 1996. Dr. G. Fred Hrusa, the recently retired Senior Plant Taxonomist, arrived in 1997 and retired in 2016, and Dr. Dean Kelch was employed briefly as a Plant Taxonomist from 2006-2011. The current Senior Plant Taxonomist is Dr. Genevieve Walden, who arrived in 2017.

The Botany Lab has completed a long term project to database the entire collection and make the data available on the Web as part of the Consortium of California Herbaria , which provides plant specimen data from (currently) 18 different California herbaria. One-stop shopping for botanical information will revolutionize our ability to understand plant distribution and systematics in California. This outreach to other botanical institutions is an example of forming alliances with other organizations and increasing the use and relevance of the CDA Herbarium to the California community.

Visits to use the CDA collection should be arranged in advance. Because plant specimens can last indefinitely if properly cared for, visitors must be conversant with and use best specimen handling techniques, or they must undergo instruction in handling specimens.

As CDA is a diagnostic, working collection, loans of specimens are only available for short periods. Material borrowed from CDA is a loan between institutions, not between individuals. Loan request letters are from a designated representative of the institution (e.g., Director of the Herbarium), and the institution accepts responsibility for the proper care and timely return of borrowed specimens. Unless agreed to in advance, all loans are expected to be fully annotated prior to return. Removal of material for destructive sampling (e.g., molecular analysis) also requires prior approval from the lending institution. If you wish to borrow specimens, contact the herbarium curator for further details and instructions.