Black olive is a 40 to 50-foot-tall evergreen tree with a smooth trunk holding up strong, wind-resistant branches, forming a pyramidal shape when young but developing a very dense, full, oval to rounded crown with age. Sometimes the top of the the crown will flatten with age, and the tree grows horizontally. The lush, dark bluish-green, leathery leaves are two to four inches long and clustered at branch tips, sometimes mixed with the 0.5 to 1.5-inchlong spines found along the branches.”