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The Center for Plant DiversityFloral collage

You press em, we guess em

Using the UC Davis Center for Plant Diversity Herbarium Facilities

The herbarium's official hours are 9 a.m. 12 p.m. and 1 pm - 4 p.m. daily. Directions and map are provided here (Driving Directions and Map). Any member of the public is welcome to use the herbarium. If you have not visited the herbarium previously, we ask that you make an appointment with us by calling us at 530-752-1091 or emailing Alison Colwell,

For our visitor orientation document click here. The first time that you visit, we will advise you of certain policies such as:

  • Incoming dried plant material must be frozen at minus 20 degrees Fahrenheit for one to two weeks prior to using it in the herbarium. We will be glad to freeze your plant material for you and then place it in a cabinet for your use. Please email Teri Barry,, to make arrangements for freezing specimens.
  • All plant specimens must be stored in herbarium cabinets, when not in use. Leaving plant specimens on counters overnight exposes them to herbarium beetles; we will need to refreeze any plant material that is left out overnight.
  • When looking through our specimen folders, please do not turn herbarium specimens over like book pages; keep them face-up.
  • Please keep track of where you take specimens from in the cabinets and re-file them carefully. We will explain our filing system to you, on your first visit. The misfiling of specimens can result in the specimens being lost for decades.

Plant Identification Services

Any person can use our facilities to identify plants they have collected, and we are happy to assist you by pointing you to the correct family or genus, showing you how to use the microscopes and collections, and providing you with appropriate identification keys. Fresh plant material can be examined in our identification lab. Dried material needs to be frozen for one to two weeks, before it can enter our main collection and plant identification lab. Please email Teri Barry,, to make arrangements for freezing specimens.

If you need our staff to identify plant samples for you, we ask that you leave your sample with us. Samples that are dropped off in person for identification can be fresh or dried. Plants mailed to us for identification should be flattened in folded newspaper or taped to paper and securely fastened between two cardboards and sent in a padded envelope or box. Plants placed in plastic bags and sent through the mail often mold. With any sample, please include date and location of collection (including county and elevation) and your contact information (email preferred).

  • United States Postal Service Mailing Address:
    UC Davis Center for Plant Diversity,
    Plant Sciences Mail Stop 7, One Shields Ave.
    Davis, CA 95616.
  • Private Mail Carrier/Delivery Address (for example UPS or Fed Ex):
    UC Davis Center for Plant Diversity
    1026 Sciences Laboratory Building
    505 Hutchison Drive, UC Davis Campus
    Davis, CA 95616.


We perform plant identifications for UC Cooperative Extension staff without charge. For other faculty, staff, students, and the public, we perform five plant identifications per year without charge; after the first five identifications, we have an hourly rate that we charge for plant identification services.
Please contact Alison Colwell,, for information about rates and services.

For Researchers Wishing to Press, Dry, and Donate Plant Specimens

We have plant presses that can be checked out for several months at a time. If you need a plant press for a year or longer, it is best to purchase your own. We are happy to instruct you in correct plant press use and specimen preparation, and we have a plant drier that you can use in room 1024. For UC Davis affiliates, there is no charge for borrowing a plant press; for others, a deposit of $50 is requested.

If you are going to collect specimens for donation to the herbarium, please consult with us about how to press specimens and what label data is required, prior to beginning your project. We have a user-friendly label-generating database that you can use to make your labels. Information about label data is provided here: Labeling Expectations

Loans of UC Davis Center for Plant Diversity Herbarium Specimens

The Center for Plant Diversity will loan specimens to other herbaria recognized in Index Herbariorum, after we have received a written request from your herbarium Director or Curator. Information on requesting our specimens on loan is provided here: Loan Guidelines for Borrowing UC Davis Center for Plant Diversity Specimens.

Policy on destructive sampling: We must be consulted prior to removal of plant parts from our specimens. Removal of plant parts may only be done if there is sufficient material available. Material may not be removed from type specimens, important historical specimens, or taxa represented by only one specimen in our herbarium. Our destructive sampling policy is provided here: UC Davis Center for Plant Diversity Destructive Sampling Policy.

Requests of Loans from other Institutions for use by UC Davis Researchers

The Center for Plant Diversity will borrow specimens from other herbaria recognized in Index Herbariorum for the use of UC Davis Researchers. Information on requesting specimens from other institutions is provided here: Procedure for UC Davis Researchers Who Wish to Borrow Herbarium Specimens from Other Institutions.