Lavender

Lavender (Lavandula angustifolia) is a low, densely branched aromatic subshrub 0.3–1 m tall, square in its young growth and woody at the base. The opposite leaves are narrow-linear to lanceolate, 2–8 cm long, grey-green, finely downy beneath and dotted with oil glands; the blades are almost stalkless with slightly rolled-back margins. The inflorescence is a firm 4–8 cm terminal spike made up of closely packed whorls with purple bracts and calyces. The flowers are small and two-lipped, deep violet-blue, with four stamens and one ovary, and a distinctly 13-ribbed calyx. It blooms from June to August in the Northern Hemisphere, and its long taproot makes the plant drought-tolerant.

According to Kew's Plants of the World Online the native range of Lavandula angustifolia runs from north-eastern Spain to Italy in the temperate biome — the limestone hills and inland belt of the western Mediterranean. Major commercial growing regions are Haute-Provence (France), the Kazanlak Valley (Bulgaria), the plains of Castile (Spain), Italy and England, while in Asia the species is also cultivated in Xinjiang and Yunnan (China). A distinction is drawn between true lavender, which gives the premium, refined oil, and the hybrid lavandin (Lavandula × intermedia), a cross between L. angustifolia and L. latifolia that yields more oil and accounts for most industrial production.

True lavender oil contains a combined 60–75% of linalool and linalyl acetate, the two components that dominate its soft, clean, sweet floral character, accompanied by low levels of camphor, 1,8-cineole, terpinen-4-ol, lavandulol and lavandulyl acetate. ISO 3515 specifies the oil of Lavandula angustifolia and tightly limits pungent components such as camphor to guarantee a premium grade. Linalool is a monoterpene alcohol with mild sedative and anxiolytic action; linalyl acetate is a readily volatile ester that, with linalool, forms the principal fraction. The glandular trichomes on flowers and leaves hold the oil, reaching peak density and content at full bloom, so harvest timing determines oil quality.

Lavender is used in perfumery as a base note and fixative, in cosmetics, soaps, linens and sachets, in cooking in small amounts (bakes and drinks), and through lavender honey. On the medical side, the review by López et al. (Frontiers in Pharmacology, 2017) sets out the central-nervous-system targets of the oil, in which linalool and linalyl acetate act on GABAergic and serotonergic systems and on NMDA receptors. The randomised, double-blind, controlled trial by Kasper et al. (International Journal of Neuropsychopharmacology, 2014) showed that oral lavender oil capsules (Silexan) significantly reduce symptoms in generalised anxiety disorder, against placebo and with efficacy comparable to paroxetine. The review of clinical studies by Manzoor et al. (Food Science & Nutrition, 2025) reinforces the anxiolytic effect, while Sanna et al. (Frontiers in Pharmacology, 2019) recorded relief of neuropathic pain in a mouse model.

On safety, linalool and linalyl acetate in the oil oxidise on prolonged exposure to air to form hydroperoxides, which are well-documented contact allergens; fresh oil should be used, properly diluted, patch-tested on skin, kept away from the eyes and out of children's reach. Cases of prepubertal breast development in boys have been reported in connection with topical products containing lavender oil, so it should not be applied to children over long periods. The oil should not be taken internally except in controlled preparations, and pregnant women and people on sedatives should use it with caution. For conservation, the IUCN lists the species as Not Evaluated and it is absent from CITES; commercial plantings cover tens of thousands of hectares in France, Bulgaria and Spain and wild collection is only local, but genetically pure wild stands risk being diluted by crosses with lavandin.