Lavender, also known as Lavandula, is a group of 47 types of plants that grow back every year. These plants belong to the sage family, called Lamiaceae. They are originally from the Old World, which includes areas like Europe, Africa, and Asia. They are mostly found in dry, warm regions around the Mediterranean Sea and enjoy sea breezes.

Lavender grows in places like the Iberian Peninsula and along the entire Mediterranean coastline. This includes areas such as the Adriatic coast, the Balkans, the Levant, and coastal North Africa. It is also found in parts of Eastern and Southern Africa, the Middle East, South Asia, and the Indian subcontinent.

Many lavender plants are grown in temperate climates for use in gardens and landscapes. They are also used as herbs in cooking and for making essential oils. Additionally, lavender is used in traditional medicine and in cosmetics.

Description

The genus includes plants that live for one year or a few years, such as herbaceous perennials, and some that look like shrubs.

Leaf shape varies widely. Some species have simple leaves, while others have leaves that are pinnately toothed or pinnate, sometimes with many divisions. In most species, the leaves are covered in fine hairs or a layer of tiny structures called indumentum, which usually contain essential oils.

Flowers grow in clusters called whorls, which are on spikes that rise above the leaves. Some spikes have branches. Some species have colored bracts at the ends of these clusters. The flowers may be blue, violet, or lilac in wild species, occasionally blackish purple or yellowish. The calyx is a tube-shaped structure. The corolla is also tube-shaped, usually with five lobes (the upper lip often split, and the lower lip has two splits).

Over 93 different chemicals have been found in lavender oil. The main ones include linalyl acetate (30–55%), linalool (20–35%), tannins (5–10%), and caryophyllene (8%). Other chemicals present in smaller amounts are sesquiterpenoids, perillyl alcohols, esters, oxides, ketones, cineole, camphor, beta-ocimene, limonene, caproic acid, and caryophyllene oxide. The amounts of these chemicals can vary a lot between different lavender species.

Taxonomy

Lavandula stoechas, L. pedunculata, and L. dentata were known during Roman times. From the Middle Ages until the 1700s, European species were divided into two groups: Stoechas (including L. stoechas, L. pedunculata, and L. dentata) and Lavandula (including L. spica and L. latifolia). Carl Linnaeus later grouped these species together in his work Species Plantarum (1753). He identified five species: L. multifida and L. dentata from Spain, and L. stoechas and L. spica from Southern Europe. L. pedunculata was grouped under L. stoechas.

By 1790, two more species, L. pinnata and L. carnosa, were recognized. L. carnosa was later moved to a different genus called Anisochilus. In 1826, Frédéric Charles Jean Gingins de la Sarraz listed 12 species divided into three groups. By 1848, 18 species were known.

In 1937, Dorothy Chaytor at Kew Gardens created one of the first modern classifications. She divided 28 species into six groups, but many plants did not fit neatly into these groups. Her groups included Stoechas, Spica, Subnudae, Pterostoechas, Chaetostachys, and Dentatae. Most garden and commercial lavender varieties were found in the Stoechas and Spica groups. Stoechas included four species: L. stoechas, L. dentata, L. viridis, and L. pedunculata. Spica included three species: L. officinalis (now called L. angustifolia), L. latifolia, and L. lanata. Chaytor believed garden varieties were hybrids between L. angustifolia and L. latifolia.

Lavandula has three main groups:
– Subgenus Lavandula: Mostly woody shrubs with whole leaves. These include the main species grown for decoration and oils. They are found in the Mediterranean, northeast Africa, and western Arabia.
– Subgenus Fabricia: Includes shrubs and herbs, found from the Atlantic to India. Some are used for decoration.
– Subgenus Sabaudia: Contains two species in southwest Arabia and Eritrea. These are distinct and sometimes placed in their own genus, Sabaudia.

Many hybrids and special varieties are used in commercial and garden settings.

The first major group includes Subgenus Lavandula, and the second includes Subgenus Fabricia. The Sabaudia group is less clearly defined. Within the Lavandula group, smaller groups match existing sections, but Dentatae is separate from Stoechas. Within Fabricia, smaller groups match Pterostoechas, Subnudae, and Chaetostachys.

Today, 39 species are classified into 8 sections (including the original 6 by Chaytor and 2 new sections by Upson and Andrews) across three subgenera. However, lavender plants often cross-pollinate, creating many variations that make classification difficult.

This classification is based on the work of Upson and Andrews in 2004.

Etymology

The English word "lavender" began being used in the 13th century. It is believed to come from the Old French word "lavandre," which is ultimately linked to the Latin word "lavare," meaning "to wash." This refers to how people used blue liquid from lavender plants for bathing. The scientific name "Lavandula," first used by Linnaeus, is thought to come from this and other European names for the plant.

Common names like "English lavender," "French lavender," and "Spanish lavender" are not always accurate. "English lavender" is often used for the species L. angustifolia, though some sources call it "Old English lavender." "French lavender" can refer to either L. stoechas or L. dentata. "Spanish lavender" may refer to L. pedunculata, L. stoechas, or L. lanata.

Cultivation

The most common type of lavender grown in gardens is called common or English lavender, scientifically named Lavandula angustifolia (previously known as L. officinalis). Many different varieties of this plant are available. Other lavender species often grown for decoration include L. stoechas, L. dentata, and L. multifida (also called Egyptian lavender).

Because these plants are widely planted in gardens around the world, they sometimes grow in the wild outside their natural areas. This type of growth is usually not harmful, but in some places, lavender species have become invasive. For example, in Australia, L. stoechas has spread widely across the country and has been labeled a noxious weed in Victoria since 1920. It is also considered a weed in parts of Spain.

Lavender grows best in dry, well-drained soils that are sandy or gravelly, and it needs plenty of sunlight. English lavender takes 14 to 28 days to sprout and reaches maturity in 100 to 110 days. All lavender types require little or no fertilizer and need good air flow around them. In areas with high humidity, root rot caused by fungus can be a problem. Organic mulches, like compost, may trap moisture near the plant’s base and increase the risk of root rot. Using gravelly materials, such as crushed rocks, works better. Lavender grows best in soils with a pH between 6 and 8. Most lavender is picked by hand, and the best time to harvest depends on how the plant will be used.

Health risks

The U.S. National Center for Complementary and Integrative Health (NCCIH) says lavender is probably safe when used in food amounts. However, using lavender on the skin might cause allergic reactions. The NCCIH does not suggest using lavender during pregnancy or while breastfeeding because there is not enough information about its effects. It also advises caution when young boys use lavender oil, as it might affect hormones and lead to breast tissue swelling.

A 2007 study looked at how different fragrances affect skin sensitivity to sunlight. It found that lavender can cause skin reactions when exposed to sunlight but does not cause a specific type of blood reaction.

Some people may develop skin irritation, eczema, or facial skin issues after applying lavender oil to their skin.

Uses

Lavender is grown mainly to produce essential oil, which is used in products like perfumes, cosmetics, and topical treatments. English lavender (Lavandula angustifolia) produces oil with a sweet scent. Another type, Lavandula × intermedia (also called lavandin or Dutch lavender), is a mix of English lavender and another species. Lavandin flowers are larger and easier to harvest than English lavender. Its oil has a similar scent but contains more chemicals, such as camphor, which give it a sharper smell. Some people consider this scent less desirable than that of English lavender.

The U.S. Food and Drug Administration says lavender is safe for human use. During World War I, lavender essential oil was used in hospitals.

Culinary lavender is usually English lavender, specifically the variety L. angustifolia 'Munstead'. It has a sweet, citrus-like scent and is used in cooking, such as in pasta, salads, desserts, and teas. Its buds and leaves are used to make tea, and bees use its flowers to produce a special type of honey called monofloral honey.

Spanish nard, also known as L. stoechas, is mentioned in an old recipe for a spiced wine called hippocras.

Lavender was brought to England in the 1600s. Queen Elizabeth I of England enjoyed lavender jam, and lavender was used in teas for both taste and health.

In the early 1900s, lavender was not commonly used in traditional southern French cooking. However, French sheep are sometimes allowed to graze on lavender, which is believed to make their meat more tender and fragrant. In the 1970s, a blend of herbs called herbes de Provence was created. Culinary lavender is added to this blend in North America.

Today, lavender is used worldwide to flavor tea, vinegar, jellies, baked goods, and drinks. For cooking, dried lavender buds (also called flowers) are most often used. Drying increases the strength of the buds’ flavor, so they should be used sparingly to avoid a soapy taste. Recipes that call for fresh lavender buds usually use one-third the amount of dried buds.

Lavender can enhance both sweet and savory dishes. It pairs well with cheeses made from sheep’s or goat’s milk. Lavender is sometimes added to black, green, or herbal teas. It is used in baked goods, especially with chocolate, and in the United States, lavender syrup and dried buds are used to make scones and marshmallows.

To flavor sugar, lavender buds are placed in sugar for two weeks. The sugar is then used in baking. Lavender can be used in bread recipes that call for rosemary. It is also used decoratively in dishes, spirits, or as a garnish for champagne. Lavender adds flavor to savory dishes like stews and sauces, and it is used to scent desserts such as flans, custards, and sorbets.

Lavender flowers produce a lot of nectar, which bees use to make high-quality honey. This honey is mainly made in the Mediterranean region and sold globally as a premium product. Lavender flowers can be candied and used as cake decorations or to make "lavender sugar."

In traditional medicine, lavender flowers are used to help with restlessness, insomnia, digestive issues, and certain heart conditions.

Dried lavender flowers are used in flower arrangements, potpourri, and sachets to freshen clothes and deter moths. They are also used as wedding confetti and in scented waters, soaps, and sachets.

In culture

The ancient Greeks named the lavender herb νάρδος, which became nardus in Latin, after the Syrian city of Naarda (possibly the modern town of Duhok, Iraq). It was also often called nard. The type of lavender originally grown was L. stoechas.

During Roman times, lavender flowers cost 100 denarii per pound. This was roughly equal to a month’s wages for a farm worker or the cost of fifty haircuts from a local barber. Its late Latin name was lavandārius, derived from lavanda (things to be washed), which comes from the verb lavāre (to wash).

The plant and its color have been used to represent the LGBTQ community in events such as the Lavender Scare and lavender marriage, as well as other symbols since the 19th century.

Gallery

• Lavender flower
• Flower from cultivated lavender, specifically the species Lavandula stoechas
• Flower from Lavandula angustifolia, a type of lavender
• A lavender plant growing near a mosque in Mostar, Bosnia and Herzegovina
• Bunches of lavender for sale, used to keep insects away
• Lavender products being sold at a farmers market