Leaves have a single main vein rising from the leaf base. The thick, firm evergreen leaves are hairless, oval, and up to an inch wide, with smooth margins. The bark is smooth and olive green, giving rise to its common name. The stem is a rough-barked trunk near the base. Branches are stiff and sharp, or spiny, at the tips.
"Ceanothus" means "spiny plant" in Greek, and the species name,
"spinosus", means that it is even more spiny. The
stipules (small leaf-like structures at the base of the leaf stem) are thin and fall off early. ==Inflorescence and fruit==