The roots may be divided either in spring or autumn. Though Lavender grows most luxuriantly in rich soil, the plants are more highly aromatic, and less liable to injury from severe weather, when grown in light, warm, and gravelly situations.
Use.—Lavender is sometimes used as a pot-herb, "but is more esteemed for the distilled water which bears its name, and which, together with the oil, is obtained in the greatest proportion from the flower-spikes which have been gathered in dry weather, and just before the flowers are fully expanded. The oil of lavender is obtained in the ratio of an ounce to sixty ounces of dried flowers."—Law.
"In the neighborhood of Mitcham, in Surrey, England, upwards of two hundred acres are occupied with Lavender alone."—Thomp.
Varieties.—
Broad-Leaved Lavender. Mill.
Spike Lavender.
Compared with the Common Lavender, the branches of this variety are shorter, more sturdy, and thicker set with leaves; the latter being short and broad.
The Broad-leaved Lavender rarely blossoms; but, when this occurs, the leaves of the flower-stalk are differently formed from those of the lower part of the plant, and somewhat resemble those of the Common variety. The stalks are taller, the spikes lower and looser, and the flowers smaller, than those of the last named.
Common or Blue-Flowering Lavender.
Narrow-leaved Blue-flowering.