Henna

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{{Taxobox | color = lightgreen | name = Henna | image = Lawsonia inermis Ypey36.jpg | image_width = 240px | image_caption = Lawsonia inermis | regnum = Plantae | divisio = Magnoliophyta | classis = Magnoliopsida | ordo = Myrtales | familia = Lythraceae | genus = Lawsonia | species = Lawsonia inermis | species_authority = L. }} 'Henna' (Lawsonia inermis, syn. L. alba) is a flowering plant, the sole species in the genus Lawsonia in the family Lythraceae. It is native to tropical and subtropical regions of Africa, southern Asia and northern Australasia with an arid or at least seasonally dry climate.

It is a shrub growing to 6 m tall. The leaves are in opposite decussate pairs, oval, 2–4 cm long and 1.5–3 cm broad, with an entire margin and acute apex. The flowers are fragrant, produced in conical panicles 10–40 cm long, each flower 5 mm diameter, with four white petals. The fruit is a dry capsule 6–8 mm diameter, containing numerous 1–2.5 mm seeds.

Contents

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Cultivation and uses

Henna is used as a dye, particularly in hair colouring, and temporary body art known as mehndi (also written as mehendi or mehandi). The dye is extracted from the dried leaf and petioles of the plant. The natural dye is traditionally found in India, Pakistan, Iran, and North Africa, and also in expatriate communities from these countries.

The application of henna to goat skin bags, after they have been salt-cured, is supposed to "insect-proof" or "moth-proof" the bags, by making the skin poisoned or inedible. This has been observed with bagpipe bags from Tunisia the "Zukra" or "Mezoued", and Iran on the "Nay-anban" or "Habouneh" (and many other spellings).

The United States Food and Drug Administration has not approved henna for direct application to the skin, but only for adding a deep red or brown tint and shine to hair. Most other cultures consider naturally-made henna to be harmless, though some products known as black henna with added paraphenylenediamine have been adulterated and can cause allergic reactions and permanent tissue damage.

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Properties and chemistry

Image:Henna for hair.jpg To create henna, the leaves are dried and ground into a powder that is greenish-brown. Strong tea, lemon juice and essential oils (such as tea tree and lavender) can be added to release the dye from the powder, and sugar is mixed in to produce a mud-like consistency. The resulting paste needs to set for about 24–30 hours at room temperature to allow the dye to release fully. This can be sped up to as little as 1 hour by warming the mixture to 40 °C.

When used on skin, henna penetrates only the dead cells of the stratum corneum, a layer which is thickest on the hands and feet, especially for males. How long the paste is left on the body affects the depth of penetration, and the stain will last longer when fully absorbed in thick skin.

Allergic reactions to natural henna are rare, and typically do not cause serious health effects. Symptoms are usually apparent within a few hours, and are generally limited to mild itching, shortness of breath, and/or tightness in the chest.

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Use of henna as body art

Image:Mehndi.jpg Mehndi is the application of henna as a temporary form of skin decoration. This usage is popular in the Middle East, North Africa and South Asia as well as expatriate communities from these areas. It is usually drawn on the hands and feet, where the designs will last the longest.

Henna paste is usually applied to the skin using a plastic cone or a paint brush, but sometimes a small metal-tipped jacquard bottle used for silk painting (a jac bottle) is used. The affected area is then wrapped with tissue, plastic, or medical tape to lock in body heat, creating a more intense colour on the skin. The wrap is worn overnight and then removed. The final colour is reddish brown and can last anywhere from two weeks to several months depending on the quality of the paste.

The patterns of Mehndi are typically quite intricate, and predominantly applied to brides before wedding ceremonies. However, traditions in Bangladesh, Kashmir and Sudan sometimes expect bridegrooms to be painted as well. In Rajasthan (northwest India), where mehndi is a very ancient folkart, the grooms are given designs which are often as elaborate as those for brides. In Kerala (South India), Henna is known as Mylanchi and is commonly used by the Mappila (Muslim) community during weddings and festivals.

Mehndi decorations became fashionable in the West in the late 1990s, where they are sometimes called "henna tattoos". This American marketing slang is inaccurate, since tattoos are defined as permanent surgical insertion of pigments underneath the skin.

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Black henna

"Black henna" is the name given to an artificial product created by the addition of paraphenylenediamine (PPD) to natural henna to create a black stain. PPD is traditionally used in black hair dye but is a sensitizer, which means that it is something that the body is naturally allergic to or can become allergic to. Black henna can cause severe reactions that can take from 5–15 days to appear, which can cause permanent scarring and may even be life threatening. Reactions to black henna frequently necessitate immediate medical attention from a doctor or allergist.

However, other dyes exist which are sometimes called "black henna," which are usually composed of a mixture of henna and indigo. These generally do not contain PPD.

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See also

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External references

General
Mehndi (body art)
Hair
Safety

da:Henna de:Henna es:Henna fa:حنا fr:Henné ko:헤나 he:חינה nl:Henna ru:Хна fi:Henna sv:Henna

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