Welcome to the Urban Tree Key, a resource for identifying the 250 most common urban tree species in California!

When you're trying to identify a particular tree, answer each question as best as you can based on the descriptions and photographs. Eventually, you'll come to a list of possible species and a few characteristics for each that distinguish it from the rest; there are photos to illustrate those differences.

Examine your specimen to see which of the distinguishing characteristics it has. Confirm (or reject) your selection by clicking on the species name and checking out the full description.

Once you know your way around, you can use the Overview link to see the whole Tree Key to save some time.

Use the Contact Us link to make a suggestion or ask a question.