Lavandula is a genus familiar to almost everyone through its use as a garden plant and in toiletries and household products. It consists of 20 species of small- to medium-sized shrubs, typically with linear, grey-green leaves and upright stems bearing scented flowers held in compact spikes. These are usually purple but may also be pink or white.
Distinctive species include Lavandula stoechas, with inflorescences topped by tufts of bracts, and Lavandula canariensis, which has deeply cut, feathery foliage. Native to the Mediterranean, Middle East and Africa, lavenders thrives in hot dry climates and thin, well-drained soils. It makes an undemanding garden plant, needing minimal feeding or watering.
The name lavender derives from the Latin 'lavare', to wash, as the Romans used the plant in baths and for washing clothes, and it remains a common ingredient in soaps and cleaning products thanks to its distinctive scent. It was traditionally considered to be antiseptic and an insect repellent, and was strewn on floors and burnt in sickrooms to deter infection. Recent research has shown that lavender oil is antimicrobial. Human use of lavender against insects and micro-organisms represents our commandeering of the plant's own defence chemicals, intended to protect it from attack while alive.
Many medicinal uses have been attributed to Lavandula. Some of the complaints it was believed to cure include colic, toothache, headache, and palsy. It is still commonly used as a treatment for anxiety and insomnia, a practice which is endorsed by medical organisations, including the WHO. A 2018 study showed the scent of lavender can reduce anxiety in mice, and suggested that it could in future be used clinically in humans as an alternative to existing anti-anxiety drugs, many of which cause unpleasant side effects. The development of scientific support for centuries-old plant uses shows that 'folk' remedies can represent a valid resource for medical and pharmaceutical innovation.
Today, lavender is grown commercially in many countries, including England, where it produces a high-quality crop despite the cooler climate. Eighteenth-century sources indicate that English lavender was favoured over that grown in mainland Europe, and commanded a much higher price. Although production of English lavender declined severely in the twentieth century, it has recently enjoyed a resurgence, with many new farms becoming established. Lavandula angustifolia and Lavandula x intermedia are the species most commonly grown commercially, and several cultivars exist which have been selected for improved oil or flower production.
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