I used to be very dismissive of parsley as the poor cousin of coriander because of those awful, raw decorative sprigs stuck on top of fish, but the more you work with parsley the more you appreciate its subtlety.
Curly leaf parsley plants
Flatleaf parsley leaves
Parsley is of Southern European (probably Eastern Mediterranean) origin and became popular in more Northern latitudes in the Middle Ages when it was grown in monasteries and Imperial gardens according to Charlemagne's Capitulare de Villis. Today, two different varieties are grown. Root parsley var. tuberosum has a tender, edible root which is used as an aromatic vegetable. Leaf parsley is solely cultivated for its leaves (chopped for use as a garnish in many European countries) and has a small, tough, woody inedible root.
Leaves, root and (occasionally) fruits. Dried leaves have little or no fragrance.
Apiaceae (parsley family).
All parts of the plant exhibit the same characteristic aroma, strongest in the root.
The botanical genus name petroselinum is the classical Latin name for the parsley plant and was loaned from Greek petroselinon "parsley", in turn composed from petros "rock" or "stone" and selinon "celery". The second part of the genus name, selinon, is not only translated as "celery" but also as "wild parsley" and it seems that little distinction was made between those two in Ancient Greece. The word appears in Homer's Odyssey, where the herb decorates the shore of the island Ogygia, home of the beautiful nymph Kalypso.
The species name crispus "crispate" was given because of the crispate leave shape, a tendency much increased in some cultivars "curly parsley".
Greek petroselinon and its Latin adaptation petroselinum are the source of most names of the herb in modern European tongues, e.g. English "parsley", Swedish persilja, Spanish perejil, Basque perrexil and Russian petrushka. The name was also loaned to some Semitic tongues, e.g. Hebrew petrosilia and Amharic peterzili. The most Eastern representatives of that kin are Indonesian peterseli, Japanese paseri and Korean pasulli.
Surprisingly, Modern Greek has an unrelated name for parsley which shows no relation to the Ancient Greek name, regional variations on this name including maidanos and maidano. This name is a loan from Turkish, where the parsley is known as maydanoz. The Turks came to know parsley only via the Greeks in Macedonia, so the Turkish name originally meant "Macedonian herb". With the expansion of the Ottoman Empire, the Turkish name spread to languages of South-Eastern Europe and the Orient, e.g. Bulgarian magdanoz, Armenian maghatanos, Albanian majdanoz and Arabic baqdunis.
Some Central Asian languages have names for parsley which are unrelated to both Greek petroselinon and Turkish magdanoz, but form a third group. These include Azerbaijani cəfəri, Kurdish ja'fari, Farsi jaafari and possibly also Kazakh zäjaba. The basis for this group of names is unknown.
In countries which have no traditional use for parsley, the herb is often named as a variant of coriander which has similar-shaped leaves and which can be used similarly to parsley leaves, e.g. Khmer vanns baraig "foreign coriander" or Vietnamese rau mui tay "Western coriander". A similar idea is expressed by Chinese ou qin "European celery". Two other names, Thai phakchi farang and Chinese yang yuan sui both mean "Western coriander", but may denote both parsley and the long coriander of Mesoamerican origin. In the opposite way, coriander is often termed "Indian parsley" (or similar) in Western countries.
Parsley has been known for millennia in the Mediterranean and its usage for cultic purposes dates back to Ancient Greece. Chopped parsley leaves are used today as a popular food decoration in Central Europe (similar to the use of coriander leaves in China, South-East Asia and parts of India), mostly for soups and vegetables.
French chefs frequently combine parsley with other fresh herbs (e.g. chervil or lemon balm) or use the classical composition fines herbes, a mixture that substitutes for plain parsley leaves to give dishes a richer aroma and more Mediterranean character. The famous French recipe sauce béarnaise also makes use of fresh parsley leaves.
As parsley aroma suffers from prolonged heat treatment, parsley leaves should not generally be cooked although quick frying in olive oil is acceptable. An exception to this rule is bouquet garni, a selection of fresh herbs tied into a bundle and cooked in soups, sauces or stews. Due to the long cooking time, the aroma of the herbs merges with the flavour of the other ingredients, thereby enriching the food without being recognisable in the finished dish. Most kinds of bouquet garni contain parsley and thyme, with other components depending on the type of food and on the region.
Parsley is a common and popular herb in Western Asia and often appears in Turkish, Lebanese, Syrian and Jordanian foods, particularly cold appetisers such as hummus (flavoured chick pea purée) and baba ganoush (aubergine purée). Another famous example is tabbouleh, often regarded as the national dish of Lebanon, a salad made from bulgur wheat, onion, lemon juice, tomato, cucumber and chopped fresh parsley and mint. In Turkey, a similar salad (kısır) is prepared, the flavour and colour of which is much altered by use of tomato paste and pomegranate concentrate.
In the Caucasus, parsley is also known and popular. Dried parsley appears in the famous spice mixture from Georgia, khmeli-suneli and is also found, dried or fresh, in the Iranian herb blend ghorme.
The root of the parsley plant is either eaten as a vegetable or cooked in soup to improve the taste as it does not diminish in flavour after a long time of cooking. The fruits of the plant, although aromatic, have little culinary application. Since they are an efficient diuretic drug, large amounts of them may be hazardous, especially for people with kidney weakness. The same is to some extent true for the root, but not for the leaves.