The Urban Tree Key

The Urban Tree Key is a tool for identifying the most common urban tree species in California and the Western U.S.

Download for iPhone

A series of reference photos and simple questions about leaves, bark, tree shape etc. intuitively guide the user to the identification of more than 350 common urban tree species.

A diagram showing a conifer branch, with long leaves and a cluster of seed cones.
A yellow-green tree with small leaves in a botanical garden, with a bench and stairs nearby, under a blue sky.
Close-up of a cluster of ripening red and green berries on a plant with green leaves, labeled as Psidium cattleianum, commonly known as a berry.

They key will help you identify a tree on the spot, and learn important identifying characteristics of the species for future encounters.

Breadcrumb navigation allows for easy backtracking.

Each species in the key has a detailed page including additional photos and information about the tree, such as its native range, considerations for planting and care, and more.

Technical terms are simply defined in the linked glossary.

Download for Android
A digital quiz asking if a tree is a conifer, palm, or broadleaf, with an image of conifer branches and a cone-shaped tree with needle-like leaves.
Two sets of leaves, one with three green leaves labeled 1, 2, and 3, and another with multiple green leaves and a reddish-brown leaf on the left, each set labeled for the number of leaflets, with the first labeled "Leaflets 5 or fewer" and the second labeled "Leaflets 7 or more".