University of California, Davis herbarium vascular plant collections are worldwide, with emphasis on California, North America, and neotropics (especially Ecuador and Baja California).

Our collections are especially strong in the following taxa: Quercus, Fagaceae, and Arctostaphylos, Ericaceae of New World; Euphorbiaceae worldwide; Poaceae of North America; Streptanthaus (Brassicaceae); Clarkia (Onagraceae); Lycianthes and Lycopersicon (Solanaceae); Stephanomeria and tarweed genera (Asteraceae); Navarretia (Polemoniaceae); Allium (Alliaceae); Trifolium (Fabaceae);Prunus (Rosaceae).

Our regional strengths are: Central Valley of California vernal pool species; weedy and poisonous species of California and Mediterranean-climate regions; range plants of California; alpine flora of western North America.

Estimated size of collection: 320,000 specimens, 50% from California. 95% of the California specimens have label data online, 60% also have images online. Specimens outside of California acquired in the past 7 years have label data online and most are also imaged. 4.4% of older non-California specimens are databased. Specimens not online are imaged and databased on request.