Wild Parsnip (Pastinaca sativa) is a tall, stout, herbaceous plant with a long (up to 1.5 m), thick taproot (Gleason and Cronquist 1991). Parsnip is native to Eurasia between the western Mediterranean region and the Caucasus Mountains. It now grows wild throughout southern and central Europe and was long ago introduced into the United Kingdom and northern Europe. It is also now found growing wild in Australia, Canada and the United States, China and Japan, New Zealand, southern Africa, and southern South America. In many regions, Wild Parsnip is now viewed as a weed of concern. In North America, it is predominantly found in the eastern part of the continent, but it is widely naturalized across the United States, colonizing old fields, railroad embankments, roadsides, and waste areas. Parsnip was introduced to North America shortly after European settlement as an important root crop. It subsequently escaped cultivation and naturalized as a less palatable ‘‘wild’’ form. Wild Parsnip grows best in rich, alkaline, moist soils, but can survive under poor soil conditions and under drought conditions (perhaps as a result of its deep tap root). (Vaughan and Geissler 1997; Menemen et al. 2001 and references therein; Averill and DiTommaso 2007 and references therein)

The cultivated form of Parsnip, which has a thicker and more succulent root, is grown in temperate regions all over the world. Its root is used as animal fodder or as a cooked vegetable (delicious simply broiled with a drizzle of olive oil!). Parsnip was cultivated in Roman times, but fleshy forms were not developed until the Middle Ages. The root contains around 6% starch and 6% sugar; exposure to frost supposedly increases the conversion of starch to sugar. Vitamin C content is 17 mg/100g. Parsnip has sometimes been used to make wine. (Vaughan and Geissler 1997)

The Parsnip plant has a characteristic smell; hollow, furrowed stems; and large, simple, pinnate leaves with ovate and toothed leaflets. The small yellow flowers are borne in an umbel that may be as much as 10 cm across. (Vaughan and Geissler 1997)

Parsnip contains furanocoumarins, which deter herbivores from eating its foliage. These compounds can also cause phytophotodermatitis in humans and livestock, a condition that results in patches of redness and blisters on the skin when they come into contact with the sap or ingest parts of the plant in the presence of sunlight. (Menemen et al. 2001)

Parsnip has been the subject of diverse studies investigating the chemical ecology and evolution of plant-herbivore interactions (Zanger et al. 2008 and references therein).

Averill and DiTommaso (2007) and Cain et al. (2010) reviewed the biology and ecology of this species.

Wild Parsnip is one of eight species and four subspecies in the genus Pastinaca, all of them native to Europe and Asia (Menemen et al. 2001 and references therein).