LAVENDER, botanically Lavandula, a genus of the family Labiatae distinguished by an ovate tubular calyx, a two-lipped corolla, of which the upper lip has two and the lower three lobes, and four stamens bent downwards.
The plant to which the name of lavender is commonly applied, Lavandula vera, is a native of the mountainous districts of the countries bordering on the western half of the Mediterranean, ex tending from the eastern coast of Spain to Calabria and northern Africa, growing in some places at a height of 4,500 ft. above the sea-level, and preferring stony declivities in open sunny situations. It is cultivated in the open air as far north as Norway and Livonia. Lavender forms an evergreen under-shrub about 2 ft. high, with greyish-green hoary linear leaves, rolled under at the edges when young; the branches are erect and give a bushy appearance to the plant. The flowers are borne on a terminal spike at the summit of a long naked stalk, the spike being composed of 6-io dense clus ters in the axils of small, brownish, rhomboidal, tapering, opposite bracts, the clusters being more widely separated towards the base of the spike. The calyx is tubular, contracted towards the mouth, marked with 13 ribs and 5-toothed, the posterior tooth being the largest. The corolla is of a pale violet colour, but darker on its inner surface, tubular, two-lipped, the upper lip with two and the lower with three lobes. Both corolla and calyx are covered with stellate hairs, amongst which are imbedded shining oil glands to which the fragrance of the plant is due. The dried flowers have long been used in England, the United States and other countries for perfuming linen, and the characteristic cry of "Lavender! sweet lavender!" can still be heard in London streets in the second quarter of the loth century. In England lavender is cultivated chiefly for the distillation of its essential oil, of which it yields on an average of when freed from the stalks, but in the south of Europe the flowers form an object of trade.
In Great Britain lavender is grown in the parishes of Mitcham, Carshalton and Beddington in Surrey, and in Hertfordshire in the Parish of Hitchin, where lavender is said to have been grown in 1568, but as a commercial speculation its cultivation dates back only to 1823. The plants at present in cultivation do not produce seed, and the propagation is always made by slips or by dividing the roots.
The flowers are collected in the beginning of August, and taken direct to the still. The yield of oil depends in great measure upon the weather. From 12 to 3o lb. of oil per acre is the average amount obtained. Oil of lavender is distilled from the wild plants in Piedmont and the South of France.
Oil of lavender is a mobile liquid having a specific gravity from 0.85 to 0.89. Its chief constituents are linalool acetate, which also occurs in oil of bergamot, and linalool, C1011170H, an alcohol derived by oxidation from myr cene, CioHis, which is one of the terpenes.
Lavender water consists of a solution of the volatile oil in spirit of wine with the addition of the essences of musk, rose, bergamot and ambergris, but is very rarely prepared by distilla tion of the flowers with spirit.
In the climate of New York lavender is scarcely hardy, but in the vicinity of Philadelphia con siderable quantities are grown for the market. In American gardens sweet basil (Ocimum basilicum) is frequently called lavender.
Lavandula Spica, a species which differs from L. very chiefly in its smaller size, more crowded leaves and linear bracts, is also used for the distillation of an essential oil, which is known in England as oil of spike and in France under the name of es sence d'aspic. It is used in paint ing on porcelain and in veterinary medicine. L. Spica does not ex tend so far north, nor ascend the mountains beyond 2,000 ft. It cannot be cultivated in Britain except in sheltered situations. A nearly allied species, L. Janata, a native of Spain, with broader leaves, is also very fragrant.
Lavandula Stoechas, a species extending from the Canaries to Asia Minor, is distinguished from the above plants by its blackish purple flowers, and shortly stalked spikes crowned by conspicuous purplish sterile bracts. The Stoechades (now called the isles of Hyeres near Toulon) owed their name to the abundance of the plant growing there.
Other species of lavender are known, some of which extend as far east as to India. A few which differ from the above in having divided leaves, as L. dentata, L. abrotanoides, L. multifolia, L. pinnata and L. viridis, have been cultivated in greenhouses.
Sea lavender is a name applied in England to several species of Statice, a genus of littoral plants belonging to the family Plumba ginaceae. Lavender cotton is a species of the genus Santolina.