Cow parsnip is a tall herbaceous perennial plant,[7] reaching heights of 3 metres (10 feet).

[8] Cow parsnip has the characteristic flower umbels of the carrot family (Apiaceae), blooming from February to September.

[22] The species is native to North America, being distributed throughout most of the continental United States (except the Gulf Coast and a few neighboring states), ranging from the Aleutian Islands and Alaska in the far northwest to Newfoundland on the east coast, extending south as far as California, New Mexico, Kansas, Ohio, and Georgia.

[10] It is especially prevalent in Alaska, where it is often found growing amongst plants like devil's club, which is nearly identical in size and somewhat similar in appearance, and monkshood, a very toxic flower.

[26] The plant contains furanocoumarins such as xanthotoxin,[27] angelicin, pimpinellin and isopimpinellin, isoimperatorin, bergapten and isobergapten, 6‐isopentenyloxyisobergapten, and sphondin.

[27] Some of these furanocoumarins found in cow parsnip are known to have antimicrobial[28][27] properties and are responsible for a rash producing erythematous vesicles (burn-like blisters) and hyperpigmentation that occurs after getting the clear sap onto one's skin.

[27][31] Because of this, phytophotodermatitis causing skin blistering may occur after coming into contact with the sap on a sunny day.

[28] The thick flower stems, coming into season in early summer, can be peeled and eaten cooked when young, as was done by Native Americans.

[33] Indigenous North Americans have had a variety of uses for cow parsnip, often traveling long distances in the spring—80 kilometres (50 miles) or more—to find the succulent plant shoots.

[5] The young stems and leafstalks were peeled and usually eaten raw, while early American settlers cooked the plant.