Syringa

Syringa (lilac) is a genus of 12 currently recognized species of flowering woody plants in the olive family (Oleaceae), native to woodland and scrub from southeastern Europe to eastern Asia, and widely and commonly cultivated in temperate areas elsewhere.
The genus is most closely related to "Ligustrum" (privet), classified with it in Oleaceae tribus Oleeae subtribus Ligustrinae.
Lilacs are used as food plants by the larvae of some moth species, including copper underwing, scalloped oak and Svensson's copper underwing.
Description.
They are small trees, ranging in size from tall, with stems up to diameter. The leaves are opposite (occasionally in whorls of three) in arrangement, and their shape is simple and heart-shaped to broad lanceolate in most species, but pinnate in a few species (e.g. "S. protolaciniata, S. pinnatifolia"). The flowers are produced in spring, each flower being in diameter with a four-lobed corolla, the corolla tube narrow, long; they are monoecious, with fertile stamens and stigma in each flower. The usual flower colour is a shade of purple (often a light purple or lilac), but white, pale yellow and pink, and even a dark burgundy color are also found. The flowers grow in large panicles, and in several species have a strong fragrance. Flowering varies between mid spring to early summer, depending on the species. The fruit is a dry, brown capsule, splitting in two at maturity to release the two winged seeds.
Taxonomy and etymology.
The genus "Syringa" was first formally described in 1753 by Carl Linnaeus and the description was published in "Species Plantarum". The genus name "Syringa" is derived from Ancient Greek word "syrinx" meaning "pipe" or "tube" and refers to the hollow branches of "S. vulgaris".
The English common name "lilac" is from the French "lilac" via the Arabic ليلك ("lilak") from Persian نیلک ("nilak") meaning "bluish".
Cultivation and uses.
Lilacs are popular shrubs in parks and gardens throughout the temperate zone, and several hybrids and numerous cultivars have been developed. The term French lilac is often used to refer to modern double-flowered cultivars, thanks to the work of prolific breeder Victor Lemoine. Lilacs grow most successfully in well-drained soils, particularly those based on chalk. They flower on old wood, and produce more flowers if unpruned. If pruned, the plant responds by producing fast-growing young vegetative growth with no flowers, in an attempt to restore the removed branches. Lilac bushes can be prone to powdery mildew disease.
The wood of lilac is close-grained, diffuse-porous, extremely hard and one of the densest in Europe. The sapwood is typically cream-coloured and the heartwood has various shades of brown and purple. Lilac wood has traditionally been used for engraving, musical instruments, knife handles etc. When drying, the wood has a tendency to be encurved as a twisted material, and to split into narrow sticks.
Symbolism.
Lilacs are often considered to symbolize love (see language of flowers). In Greece, Lebanon, and Cyprus, the lilac is strongly associated with Easter time because it flowers around that time; it is consequently called "paschalia".
In the poem "When Lilacs Last in the Dooryard Bloom'd", by Walt Whitman, lilacs are a reference to Abraham Lincoln.
"Syringa vulgaris" is the state flower of New Hampshire, because it "is symbolic of that hardy character of the men and women of the Granite State."
Festivals.
Several locations in North America hold annual Lilac Festivals, including:
Species.
Species and subspecies currently accepted as of July 2016: