The lilac bush (Syringa vulgaris) was designated the official state bush of New York state in 2006. The lilac is an ornamental shrub with showy, aromatic blooms in early spring. Lilacs have a scent stronger than roses that carries quite a distance. There are over 1,000 varieties of lilacs in several colors including white and pink (the most popular colors are lilac and purple). A lilac bush can live for hundreds of years.

Originally from Europe and Asia, lilacs date back to the 1750's in America - they were planted in our first botanical gardens and both George Washington and Thomas Jefferson grew lilacs in their gardens. New Hampshire recognizes the lilac blossom as the official state flower.

Source:

Lilacs, Lilac Bush, How to Grow Lilacs: Gardeners of NY
New York State Symbols: NYS DOS Kids Facts about NY

Links:

State Flowers - 50 States List
National Flower