Lilac, a group of beautiful flowering shrubs and trees native to temperate Europe and Asia. There are about 30 species and numerous varieties of lilacs. Lilacs are grown in all temperate areas for their handsome, often fragrant, flower clusters.

The small, tubular flowers, with four spreading lobes, grow in large conical clusters. Lilac flowers are commonly of the bluish-red color called lilac, but they also appear in white, pink, red, blue, purple, violet, and yellow. Some varieties have double flowers.

The common lilac grows to 20 feet (6 m) tall and bears clusters of white or purple flowers up to 10 inches (25 cm) long. Its purple blossom is the state flower of New Hampshire. The Persian lilac has pale lilac flowers and grows to 10 feet (3 m) tall. The nodding lilac bears drooping clusters of pinkish-white flowers and grows to 12 feet (3.7 m) tall. The Pekin lilac has pale yellow flowers and grows to 15 feet (4.6 m) tall. The Hungarian lilac grows to 12 feet (3.7 m) tall and has lilac flowers.

The common lilac is Syringa vulgaris; Persian, S. persica; nodding, S. reflexa; Pekin, S. pekinensis; Hungarian, S. josikaea. Lilacs belong to the olive family, Oleaceae.