Lavandula (common name lavender) is a genus of 39 known species of flowering plants in the mint family, Lamiaceae. It is native to the Old World and is found from Cape Verde and the Canary Islands, southern Europe across to northern and eastern Africa, the Mediterranean, southwest Asia to southeast India. Many members of the genus are cultivated extensively in temperate climates as ornamental plants for garden and landscape use, for use as culinary herbs, and also commercially for the extraction of essential oils.
The most common form in cultivation is the common or English lavender Lavandula angustifolia (formerly named L. officinalis). A wide range of cultivars can be found. Other commonly grown ornamental species are L. stoechas, L. dentata, and L. multifida (Egyptian lavender).
Because the cultivated forms are planted in gardens worldwide, they are occasionally found growing wild as garden escapes, well beyond their natural range. Commonly such adventitious establishment is apparently harmless at best, but in some cases Lavandula species have become invasive. For example, in Australia, Lavandula stoechas has become a cause for concern; it occurs widely throughout the continent, and has been declared a noxious weed in Victoria since 1920. It also is regarded as a weed in parts of Spain.
Commercially, the plant is grown mainly for the production of essential oil of lavender. This has antiseptic and anti-inflammatory properties. These extracts are also used as fragrances for bath products. English lavender (Lavandula angustifolia) yields an essential oil with sweet overtones, and can be used in balms, salves, perfumes, cosmetics, and topical applications. Lavandin, Lavandula × intermedia (also known as Dutch lavender), yields a similar essential oil, but with higher levels of terpenes including camphor, which add a sharper overtone to the fragrance. The lavandins Lavandula × intermedia are a class of hybrids of L. angustifolia and L. latifolia.
Lavender lends a floral and slightly sweet flavor to most dishes, and is sometimes paired with sheep's-milk and goat's-milk cheeses. For most cooking applications the dried buds, which are also referred to as flowers, are used. Some chefs experiment with the leaves but only the buds contain the essential oil of lavender, from which the scent and flavor of lavender are derived. In the United States, both lavender syrup and dried lavender buds are used to make lavender scones and marshmallows. Lavender flowers are occasionally blended with black, green, or herbal teas.
Lavender is used extensively with herbs such as chamomile and aromatherapy. Infusions are believed to soothe insect bites, burns, and headaches. Bunches of lavender repel insects. In pillows, lavender seeds and flowers aid sleep and relaxation. An infusion of flowerheads added to a cup of boiling water is used to soothe and relax at bedtime. Lavender oil (or extract of lavender) is used to treat acne when diluted 1:10 with water, rosewater, or witch hazel; it also treats skin burns and inflammatory conditions.
A study published in 2010 investigated anxiolytic effects and influence on sleep quality. Lavender oil with a high percentage of linalool and linalyl acetate, in the form of capsules, was generally well tolerated. It showed meaningful efficacy in alleviating anxiety and related sleep disturbances.
Lavender may be very effective with wounds; however, lavender honey (created from bees feeding on lavender plants), instead of lavender essential oil has the best effects of uninfected wounds. The essential oil was used in hospitals during World War I.
The U.S. National Institutes of Health (NIH) states that lavender is considered likely safe in food amounts and possibly safe in medicinal amounts. NIH does not recommend the use of lavender while pregnant or breast-feeding because of lack of knowledge of its effects. It recommends caution if young boys use lavender oil because of possible hormonal effects leading to gynecomastia, and states that lavender can cause skin irritation.