Lavender is a hardy perennial in the Lamiaciae, or mint, family. The herb is a Mediterranean native. There are many species of lavendula which vary somewhat in appearance and aromatic quality. English lavender, L. augustifolia, also known as true lavender, is commercially valuable in the perfume industry and is a mainstay of English country gardens. French lavender, L.stoechas, is the species most likely used in Roman times as a scenting agent in washing water. The species L. officinalis is the official species used in medicinal preparations, though all lavenders have medicinal properties in varying degrees.
This fragrant, bushy shrub has been widely cultivated for its essential oil. The tiny, tubular, mauve-blue blossoms grow in whorls of six to ten flowers along square, angular stems and form a terminal spike. These flower spikes stretch upward beyond the 12-18 inch (3.6-5.4 m) height of the shrub, blooming from June to August. The blossoms are well liked by bees and a good source of honey. The needle-like, evergreen, downy leaves are a light, silver-gray. They are lanceolate, opposite, and sessile, and grow from a branched stem. The bark is gray and flaky. The herb thrives in full sun and poor soil. Ancient Greeks and Romans used lavender blossoms to scent bath water, a common use that gave the herb its name, derived from the Latin lavare, meaning to wash.
The medicinal properties of lavender are extracted primarily from the oil glands in the leaf and blossom. The plant contains volatile oil, tannins, coumarins, flavonoids, and triterpenoids as active chemical components. These phytochemicals are the plant constituents responsible for the medicinal properties.