Persian Lilac (Syringa persica): Generally smaller, with pale lilac to white flowers. Dwarf Korean Lilac (Syringa meyeri 'Palibin'): Compact, suitable for small spaces, and highly fragrant.
When it comes to considering trees and shrubs as a hummingbird garden addition, one that offers an abundance of purple blooms that these little birds love to frequent is the dwarf Korean lilac.