Coriander (Coriandrum sativum), also commonly called cilantro in North America, is an annual herb in the family Apiaceae. Coriander is native to southwestern Asia west to north Africa. It is a soft, hairless, foetid plant growing to 50 cm tall. The leaves are variable in shape, broadly lobed at the base of the plant, and slender and feathery higher on the flowering stems. The flowers are borne in small umbels, white or very pale pink, asymmetrical, with the petals pointing away from the centre of the umbel longer (5-6 mm) than those pointing to the middle of the umbel (only 1-3 mm long). The fruit is a globular dry schizocarp 3-5 mm diameter.

The name coriander derives from French coriandre through Latin “coriandrum” in turn from Greek “κορίαννον”.

Uses

All parts of the plant are edible, but the fresh leaves and the dried seeds are the most commonly used in cooking. Coriander is commonly used in Middle Eastern, Mediterranean, South Asian, Latin American, Chinese, African and Southeast Asian cuisine.

Leaves
The leaves are variously referred to as coriander leaves, cilantro (in the United States, from the Spanish name for the plant), dhania (in the Indian subcontinent, and increasingly, in Britain), Chinese parsley or Mexican parsley. The leaves have a very different taste from the seeds, similar to parsley but "juicier" and with citrus-like overtones. Some people instead perceive an unpleasant "soapy" taste and/or a rank smell. This perception is believed to be a result of an enzyme that changes the way they taste cilantro, a genetic trait, but has yet to be fully researched.

The fresh leaves are an essential ingredient in many Vietnamese foods, Asian chutneys and Mexican salsas and guacamole. Chopped coriander leaves are also used as a garnish on cooked dishes such as dal and many curries. As heat diminishes their flavour quickly, coriander leaves are often used raw or added to the dish right before serving. (Though in some Indian and Central Asian recipes, coriander leaves are used in huge amounts and cooked till they dissolve into sauce and their flavour mellows.)

In Peruvian cuisine, the leaves are used in a great number of traditional recipes, and are known as "culantro." The seeds have also recently been incorporated into newer recipes.

Coriander leaves were formerly common in European cuisine but nearly disappeared before the modern period. Today Europeans usually eat coriander leaves only in dishes that originated in foreign cuisines, except in Portugal, where it is still an essential ingredient in many traditional dishes.

The fresh coriander herb is best stored in the refrigerator in airtight containers, after chopping off the roots. The leaves do not keep well and should be eaten quickly, as they lose their aroma when dried or frozen.

Fruit

If the spice is bought (or picked -- it can be grown in a home garden) whole in a non-dried form, it can be dried in the sun. Most commonly, it is bought as whole dried seeds, but can also be purchased in ground form. When grinding at home, it can be roasted or heated on a dry pan briefly to enhance the aroma before grinding it in an electric grinder or with a mortar and pestle; ground coriander seeds lose their flavour quickly in storage and are best only ground as needed. For optimum flavour, whole coriander seed should be used within six months, or stored for no more than a year in a tightly sealed container away from sunlight and heat.

Coriander seed is a key spice (Hindi name: dhania) in garam masala and Indian curries, which often employ the ground fruits in generous amounts together with cumin. It also acts as a thickener. Roasted coriander seeds, called dhana dal, are also eaten as a snack. It is also the main ingredient of the two south indian gravies: sambhar and rasam.

Outside of Asia, coriander seed is an important spice for sausages in Germany and South Africa (see boerewors). In Russia and Central Europe coriander seed is an occasional ingredient in rye bread as an alternative to caraway. Apart from the uses just noted, coriander seeds are rarely used in European cuisine today, though they were more important in former centuries.

Coriander seeds are also used in brewing certain styles of beer, particularly some Belgian wheat beers. The coriander seeds are typically used in conjunction with orange peel to add a citrus character to these styles of beer.

Roots
Coriander roots are used in a variety of Asian cuisine. They are commonly used in Thai dishes.

Medicinal uses
Coriander has been used as a folk medicine for the relief of anxiety and insomnia in Iranian folk medicine. Experiments in mice support its use as an anxiolytic.

Coriander essential oil showed a delay in E. Coli growth, suggesting possible agricultural anti-bacterial applications.

Coriander seeds have also been used to prepare a traditional diuretic in India . The diuretic is prepared by boiling equal amounts of coriander seeds and cumin seeds. The extract is then cooled and consumed as a diuretic.

History
Coriander is believed to have originated in the Mediterranean area, and in southwest Europe. Some believe its use began as far back as 5,000 BC, and there is evidence of its use by the ancient Egyptians. In the Bible, Exodus, chapter 16, verse 31, it says "And the house of Israel began to call its name Manna: and it was white like coriander seed, and its taste was like that of flat cakes made with honey".

Thought to have been introduced to Britain by the Romans as a meat preserver, coriander seems to have been cultivated in Greece since at least the second millennium BC. In Linear B tablets, the species is referred to as being cultivated for the manufacture of perfumes, and it appears that it was used in two forms: as a spice for its seeds and as a herb for the flavour of its leaves. This appears to be confirmed by archaeological evidence from the same period: the large quantities of the species retrieved from an Early Bronze Age layer at Sitagroi in Macedonia could point to cultivation of the species at that time (Fragiska, 2005).

Coriander seed and leaf was very widely used in medieval European cuisine, due to its ability to make spoiled meats palatable by "masking" rotten flavours. Even today, coriander seed is an important ingredient in many sausage products.

Coriander was brought to the British colonies in North America in 1670 and was one of the first spices cultivated by early settlers.

Similar plants

• Eryngium foetidum has a very similar taste to coriander and is also known as culantro.
• Vietnamese coriander leaves have a similar odour and flavour to coriander.
• Bolivian Coriander, or quillquiña, has been described as "somewhere between arugula, cilantro and rue".