Lilacs grow as medium to large shrubs or small tree, reaching a height of 4 to 20 feet, depending on the species and cultivar, and generally having a similar spread. These plants are deciduous, meaning they lose their leaves annually. Lilac bark is greenish-brown when young and becomes grayish-brown as it matures. Leaves are cordate, or heart-shaped, and 2 to 5 inches long. Lilac flowers are fragrant, appear in large panicles at the ends of branches and range in color from white to dark purple. Flowers develop into brown, woody capsules that contain flat, tannish seeds.