The Spruces are distinguished from the Firs by their depending cones growing from any of the limbs, with persistent scales and bracts, and, generally, by their scattered limbs and leaves; also by microscopic anatomy, as shown by Engelmann. They comprise two genera, Picea and Tsuga forming the second and third genera of the Abietinae, as stated, differing from each other by but few characters detected at a distance; five species in California.

Second genus, Picea, from pix, ' pitch.' The true spruce. Leaves four-sided, and generally scattered all round the long twigs, leaving, when they fall, the foot-stalk, persistent, ligneous and prominent. Bracts concealed beneath the cone-scales".