Parsley is a bright green biennial herb, often used as spice. It is common in Middle Eastern, European, and American cooking. It is used for its leaf in much the same way as coriander, although parsley has a milder flavor.
A type of parsley is grown as a root vegetable in Central and Eastern European. It produces much thicker roots than those cultivated for their leaves. Although little known in Britain and the United States it can be used in soups and stews. Parsnips are among the closest relatives of parsley, although root parsley tastes quite different.
Parsley is widely used as a companion plant in gardens. It attracts predatory insects including wasps and predatory flies to gardens, which then tend to protect plants nearby. For example, they are especially useful for protecting tomato plants as 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.
Chinese and German herbologists recommend parsley tea to help control high blood pressure, and the Cherokees used it as a tonic to strengthen the bladder. When crushed and rubbed on the skin, parsley can reduce the itching of mosquito bites. When chewed, parsley can freshen bad breath.
Parsley should not be consumed as a drug or supplement by pregnant women. Parsley is high in oxalic acid, a compound involved in the formation of kidney stones. Parsley oil contains furanocoumarins and psoralens which can lead to extreme photosensitivity if used orally.