The Garden will be closed to the public today, June 8.

purple pink and white lilac bushes

Lilac Diversity

Lilacs blooms come in many different sizes, shapes, and colors. The majority of the more than 1,600 lilac cultivars are descended from Syringa vulgaris (common lilac), the species featured prominently in this Collection, but it is only one of the approximately 21 lilac species. Most other species of lilac are native to Asia, and were unknown in the West until explorers from Europe and North America began sending home specimens and seeds. Asian lilacs typically differ from common lilac in size, flower, leaf, and fragrance. NYBG’s Collection includes Asian species such as Syringa pubescens and Syringa meyerii.

Describing and classifying the flowers of this diverse species is challenging, so breeders created color and flower form classifications. Though some lilacs fall outside of these classifications, these systems help in identifying this wide-ranging group of plants.

Flower Forms

drawings of three types of single flower types

Single flowers have four lobes (petals) that may be pointed or round, narrow or wide. Some curl inward, outward, or even twist.

Image supplied by the International Lilac Society


three drawings of double lilac flowers

Double flowers have more than four lobes, with most appearing to have two to four stacked flowers. Radial double is a rarer double form with five or more lobes, and sometimes as many as 18 radiating from the center of the flower in one layer.

Image supplied by the International Lilac Society