LAVENDER

***Lavandula*** (common name **lavender**) is a genus of 47 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, 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 widely cultivated species, *Lavandula angustifolia*, is often referred to as lavender, and there is a color named for the shade of the flowers of this species.

## Description[edit]

The genus includes annual or short-lived herbaceous perennial plants, and shrub-like perennials, subshrubs or smallshrubs.[2]

Leaf shape is diverse across the genus. They are simple in some commonly cultivated species; in other species they are pinnately toothed, or pinnate, sometimes multiple pinnate and dissected. In most species the leaves are covered in fine hairs or indumentum, which normally contain the essential oils.[2]

Flowers are borne in whorls, held on spikes rising above the foliage, the spikes being branched in some species. Some species produce coloured bracts at the apices. The flowers may be blue, violet or lilac in the wild species, occasionally blackish purple or yellowish. The calyx is tubular. The corolla is also tubular, usually with five lobes (the upper lip often cleft, and the lower lip has two clefts).[2][3]

## Nomenclature and taxonomy[edit]

*L. stoechas,* *L. pedunculata* and *L. dentata* were known in Roman times.[4] From the Middle Ages onwards, the European species were considered two separate groups or genera, *Stoechas* (*L. stoechas*, *L. pedunculata*, *L. dentata*) and *Lavandula* (*L. spica* and *L. latifolia*), until Linnaeus combined them. He only recognised five species in *Species Plantarum* (1753), *L. multifida* and *L. dentata* (Spain) and *L. stoechas* and *L. spica* from Southern Europe. *L. pedunculata* was included within *L. stoechas.*

By 1790, *L. pinnata* and *L. carnosa* were recognised. The latter was subsequently transferred to *Anisochilus*. By 1826 Frédéric Charles Jean Gingins de la Sarraz listed 12 species in three sections, and by 1848 eighteen species were known.[4]

One of the first modern major classifications was that of Dorothy Chaytor in 1937 at Kew. The six sections she proposed for 28 species still left many intermediates that could not easily be assigned. Her sections included *Stoechas*, *Spica*, *Subnudae*, *Pterostoechas*, *Chaetostachys* and *Dentatae*. However all the major cultivated and commercial forms resided in the *Stoechas* and *Spica* sections. There were four species within *Stoechas* *(Lavandula stoechas*, *L. dentata, L. viridis* and *L. pedunculata)* while *Spica* had three (*L. officinalis (now L. angustifolia), L. latifolia* and *L. lanata)*. She believed that the garden varieties were hybrids between true lavender *L. angustifolia* and spike lavender *(L. latifolia)*. [5]

More recently, work has been done by Upson and Andrews, and currently *Lavandula* is considered to have three subgenera.

* Subgenus *Lavandula* is mainly of woody shrubs with entire leaves. It contains the principal species grown as ornamental plants and for oils. They are found across the Mediterranean region to northeast Africa and western Arabia.
* Subgenus *Fabricia* consists of shrubs and herbs, and it has a wide distribution from the Atlantic to India. It contains some ornamental plants.
* Subgenus *Sabaudia* constitutes two species in the southwest Arabian peninsula and Eritrea, which are rather distinct from the other species, and are sometimes placed in their own genus *Sabaudia*.

In addition, there are numerous hybrids and cultivars in commercial and horticultural usage.[2]

## Etymology[edit]

The English word lavender is generally thought to be derived from Old French *lavandre*, ultimately from the Latin *lavare* (to wash), referring to the use of infusions of the plants.[6] The botanic name *Lavandula* as used by Linnaeus is considered to be derived from this and other European vernacular names for the plants. However it is suggested that this explanation may be apocryphal, and that the name may actually be derived from Latin *livere*, "blueish".[7]

The names widely used for some of the species, "English lavender", "French lavender" and "Spanish lavender" are all imprecisely applied. "English lavender" is commonly used for *L. angustifolia*, though some references say the proper term is "Old English Lavender".[8] The name "French lavender" may be used to refer to either *L. stoechas* or to *L. dentata*. "Spanish lavender" may be used to refer to *L. stoechas*, *L. lanata* or *L. dentata*.

## Cultivation[edit]

A bee on a lavender flower

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.[9] It also is regarded as a weed in parts of Spain.[10]

Lavenders flourish best in dry, well-drained, sandy or gravelly soils in full sun.[11] All types need little or no fertilizer and good air circulation. In areas of high humidity, root rot due to fungus infection can be a problem. Organic mulches can trap moisture around the plants' bases, encouraging root rot. Gravelly materials such as crushed rocks give better results.[12]

## Lavender oil[edit]

Main article: Lavender oil

Commercially, the plant is grown mainly for the production of essential oil of lavender. This has antiseptic[13][14] and anti-inflammatory[15] properties, and can be used as a natural mosquito repellent.[16] 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 includingcamphor, which add a sharper overtone to the fragrance.

The lavandins *Lavandula × intermedia* are a class of hybrids of *L. angustifolia* and *L. latifolia*.[17] The lavandins are widely cultivated for commercial use, since their flowers tend to be bigger than those of English lavender and the plants tend to be easier to harvest, but lavandin oil is regarded by some to be of a lower quality than that of English lavender, with a perfume less sweet.[18]

## Culinary use[edit]

Lavender infused cupcakes

Lavender is grown as a condiment and used in salads and dressings.[19] The flowers yield abundant nectar, from which bees make a high-quality honey. Monofloral honey is produced primarily around the Mediterranean, and is marketed worldwide as a premium product. Flowers can be candied and are sometimes used as cake decorations. It is also used to make "lavender sugar."[20]

Lavender lends a floral and slightly sweet flavour to most dishes, and is sometimes paired with sheep's-milk and goat's-milk cheeses. Lavender flowers are occasionally blended with black, green, or herbal teas. Lavender flavours baked goods and desserts, pairing especially well with chocolate. In the United States, both lavender syrup and dried lavender buds are used to make lavender scones and marshmallows.[21][22]

Though it has many other traditional uses in southern France, lavender is not used in traditional southern French cooking. It does not appear at all in the best-known compendium of Provençal cooking, J.-B. Reboul's *Cuisinière Provençale*.[23] In the 1970s, a blend of herbs called *herbes de Provence* which usually includes lavender was invented by spice wholesalers,[24] and lavender has more recently become popular in cooking.

For most cooking applications the dried buds, which are also referred to as flowers, are used. Only the buds contain the essential oil of lavender, from which the characteristic scent and flavour of lavender are derived. Lavender greens have a more subtle flavour that is compared to rosemary.[25] The greens are used similarly to rosemary or combined with rosemary to flavour meat and vegetables in savory dishes. They can also be used to make a tea that is milder than teas made with the flowers.[26]

## Research[edit]

Bunches of lavender for sale, intended to repel insects

Major constituents of lavender oil include linalool (26%) caryophyllene (8%).[27] The essential oil was used in hospitals during World War I.[11]

Lavender oil is under preliminary research for its possible effect in alleviating anxiety and sleep disturbances.[28] High-quality clinical research generally has not been done to conclude if there are effects of lavender oil on anxiety.[29]

## Other uses[edit]

Lavender products for sale at the San Francisco Farmers Market.

Flower spikes are used for dried flower arrangements. The fragrant, pale purple flowers and flower buds are used inpotpourris. Lavender is also used extensively as herbal filler inside sachets used to freshen linens. Dried and sealed in pouches, lavender flowers are placed among stored items of clothing to give a fresh fragrance and to deter moths. Dried lavender flowers have become recently popular for wedding confetti. Lavender is also popular in scented watersand sachets.

Lavender greens can be used in craft or modelling projects, such as the creation of miniature topiary or trees.[30]

## Health precautions[edit]

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 may cause skin irritation and could be poisonous if consumed by mouth.[31]

A 2005 review on lavender essential oil stated that, "Lavender is traditionally regarded as a 'safe' oil and, although it was recently reported that lavender oil, and its major constituent linalyl acetate, are toxic to human skin cells in vitro, contact dermatitis to lavender oil appears to occur at only a very low frequency."[32]

A 2007 study examined the relationship between various fragrances and photosensitivity, stating that lavender is known "to elicit cutaneous photo-toxic reactions", but does not induce photohaemolysis.[33]

## In history and culture[edit]

The ancient Greeks called the lavender herb *nardus*, after the Syrian city of Naarda (possibly the modern town of Dohuk, Iraq). It was also commonly called*nard*.[34] The species originally grown was *L. stoechas*.[2]

Lavender was one of the holy herbs used in the biblical Temple to prepare the holy essence, and *nard* ('nerd' in Hebrew) is mentioned in the Song of Solomon(4,14)

During Roman times, flowers were sold for 100 *denarii* per pound, which was about the same as a month's wages for a farm laborer, or fifty haircuts from the local barber. Its late Latin name was *lavandārius*, from *lavanda* (things to be washed), from the verb *lavāre* (to wash).[3