A variety of the common lilac called Yankee Doodle is wonderfully fragrant, with a single deep purple flower and grows 6-8' tall. They are of value because the flower is consistently deep purple whereas the common purple lilac has flower color that can vary from blue to purple from plant to plant.
Lilacs begin to flower relatively early in the season. They can mature anywhere from 4-12' + in height depending on variety. Flowers can be white to pink; blue to purple and wine red; variegated white and red. Some have single flowers and others have double flowers. Also, the degree of fragrance can very significantly. Some have leaves that are quite different than the typical leaf of the common lilacs.
If you like the fragrance, the flower and the unique beauty of lilacs, you can plant several varieties, so you can enjoy them for several weeks from spring through early summer.
Dorian