Parsley
Parsley (Petroselinum crispum) is a bright green, biennial herb, also used as spice. It is very common in Middle Eastern, European, and American cooking.  Parsley is used for its leaf in much the same way as coriander (which is also known as Chinese parsley or cilantro), although it has a milder flavor.

# Varieties
Two forms of parsley are used as herbs: curly leaf and Italian, or flat leaf (P. neapolitanum).  Curly leaf parsley is often used as a garnish.  Many people think flat leaf parsley has a stronger flavor, and this opinion is backed by chemical analysis which finds much higher levels of essential oil in the flat-leaved cultivars.  One of the compounds of the essential oil is apiol.
The use of curly leaf parsley may be favored by some because it cannot be confused with poison hemlock, like flat leaf parsley or chervil.

## Root parsley
Another type of parsley is grown as a root vegetable, as with hamburg root parsley. This type of parsley produces much thicker roots than types cultivated for their leaves. Although little known in Britain and the United States, root parsley is very common in Central and Eastern European cuisine, where it is used in most soups or stews.
Though it looks similar to parsnip it tastes quite different. Parsnips are among the closest relatives of parsley in the umbellifer family of herbs, although the similarity of the names is a coincidence, parsnip meaning "forked turnip". It is not related to real turnips.

# Cultivation
Parsley's germination is notoriously difficult.  Tales have been told concerning its lengthy germination, with some suggesting that "germination was slow because the seeds had to travel to hell and back two, three, seven, or nine times (depending on sources) before they could grow."  Germination is inconsistent and may require 3-6 weeks.
Furanocoumarins in parsley's seed coat may be responsible for parsley's problematic germination. These compounds may inhibit the germination of other seeds, allowing parsley to compete with nearby plants. However, parsley itself may be affected by the furanocoumarins.  Soaking parsley seeds overnight before sowing will shorten the germination period.
Parsley grows well in deep pots, which helps accommodate the long taproot. Parsley grown indoors requires at least five hours of sunlight a day.

## Companion plant
Parsley is widely used as a companion plant in gardens. Like many other umbellifers, it attracts predatory insects, including wasps and predatory flies to gardens, which then tend to protect plants nearby. They are especially useful for protecting tomato plants, for example the wasps that kill tomato hornworms also eat nectar from parsley. While parsley is biennial, not blooming until its second year, even in its first year it is reputed to help cover up the strong scent of the tomato plant, reducing pest attraction.

# Culinary uses
In parts of Europe, and particularly in West Asia, many foods are served with chopped parsley sprinkled on top. The fresh flavor of parsley goes extremely well with fish. Parsley is a key ingredient in several West Asian salads, e.g., tabbouleh which is the national dish of Lebanon. In Southern and Central Europe, parsley is part of bouquet garni, a bundle of fresh herbs used to flavor stocks, soups, and sauces.  Additionally, parsley is often used as a garnish. Persillade is mixture of chopped garlic and chopped parsley.  Gremolata is a mixture of parsley, garlic, and lemon zest.

# Medicinal uses
- Tea may be used as an enema. Chinese and German herbologists recommend parsley tea to help control high blood pressure, and the Cherokee Native Americans used it as a tonic to strengthen the bladder. It is also often used as an emmenagogue.
- Parsley also appears to increase diuresis by inhibiting the Na+/K+-ATPase pump in the kidney, thereby enhancing sodium and water excretion while increasing potassium reabsorption. It is also valued as an aquaretic.
- When crushed and rubbed on the skin, parsley can reduce itching in mosquito bites.

# Health risks
- Parsley should not be consumed as a drug or supplement by pregnant women. Parsley as an oil, root, leaf, or seed could lead to uterine stimulation and preterm labor.
- Parsley is high (1.70% by mass, ) in oxalic acid, a compound involved in the formation of kidney stones and nutrient deficiencies.
- Parsley oil contains furanocoumarins and psoralens which leads to extreme photosensitivity if used orally.