Syringa × persica
Syringa × persica, the Persian lilac, is a hybrid, thought to originate from a cross of Syringa × laciniata and S. afghanica. More compact than common lilacs, it grows up to and spreads about. Persian lilac prefers warmer winter climates than many species of lilac. Its hybrid with Syringa vulgaris, the common lilac, is Syringa ×chinensis, sometimes called Rouen lilac.
This is a different plant than Melia azedarach, also sometimes called Persian lilac.