PARSLEY

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^{[citation needed]}. 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.

(reference information from http://en.wikipedia.org/wiki/Parsley)