San Diego Natural History Museum--Your Nature Connection[BRCC San Diego Natural History Museum: Botany: Climate Change

Climate Change

Reading Room
Plant Atlas

Layla Aerne Hains
fax: 619.232.0248

Webcasts from the
Climate Change Workshop
held Nov. 7, 2007


Plant specimens consist of plants that were collected from the field, and then dried, pressed, and mounted onto archival paper along with a label describing the specimen. They are stored in cabinets in a herbarium, which is similar to a library; specimens are catalogued and can be borrowed for research purposes. Plant specimens archived in this way can last for hundreds of years, and preserve physical samples that document our floristic diversity.

Only 5% of natural history collections are estimated to be entered into computerized databases; however, thanks to a 2-year grant from the Institute for Museum and Library Services, our historic collection of plant specimens gathered within the borders of San Diego County is now completely databased.

We have almost completed another task whereby written locality descriptions such as “Point Loma lighthouse” are converted to latitude and longitude so that these older specimens can be mapped using a computer. Assigning spatial coordinates to historic specimens is known as “retrospective georeferencing.”

The Museum’s herbarium houses a research collection of 178,000 specimens of native and naturalized plants of the southwestern United States (especially southern California) and northwestern Mexico (especially Baja California). The collection consists primarily of vascular plants, with significant holdings of marine algae, mostly of the eastern North Pacific. There are about 400 type specimens.

To date, approximately 62,000 of the total collection (35%) are specimens from San Diego County. This number is always increasing, due to the activities of the San Diego County Plant Atlas project, which has contributed almost 30,000 new specimens since it began in 2002.