Longan trees grow 50 feet tall or more in some climates, but only 15 to 25 feet tall in mild, Mediterranean climates. The tree forms a dense, round or oblong canopy of evergreen foliage with a spread similar to the height. The bark is rough and corky. Glossy, dark green leaflets grow in pairs on opposite sides of leaf stems up to 1 foot long. Each stem hold six to nine pairs of 6- to 8-inch leaflets. The oblong or lancet-shaped foliage is tough and leathery with wavy margins.