Cow Parsnip - Heracleum lanatum

cow parsnip botany with brit

The inflorescence of this plant is mesmerizing, plus, it gives me the excuse to use fun words like "umbel" and "peduncle". Inflorescence is just a fancy way of saying a cluster of flowers on a branch. Cow Parsnip's flower takes the form of a compound umbel... and now what's an umbel you ask?... it's an inflorescence made up of short flower stalks spreading from a common point. Think of it as the shape your umbrella might take if you were caught in a Kansas thunderstorm and the straight-line winds turned it inside out while you held on for dear life. By now you probably don't even care what a peduncle is, but I'll tell you anyways. The peduncle is the stem supporting an inflorescence. Now you know.

Why you should care about these cool botanical terms is because they will help you recognize plants in the Parsley family (Apiaceae), and you want to recognize them for two reasons: some are extremely poisonous and some are edible. Water Hemlock is the deadliest plant in North America with Poison Hemlock not far behind, and both of these happen to be in the same family as Cow Parsnip. But our garden variety carrots, celery, and parsley are also umbel-bearing members of the Apiaceae family.


Cow Parsnip has both edible and poisonous characteristics. This plant contains a compound called furanocoumarins which make it phototoxic - in the presence of light the sap from this plant can cause blisters and hyperpigmentation of the skin. In spite of this characteristic, the plant was eaten as a green vegetable by indigenous peoples throughout the Northwest Coast. The young leaf stalks and bud stalks were picked in the spring before flowering, and they were carefully peeled before being eaten fresh. Plants growing in the shade remain edible longer and are more tender than those growing in direct sun. Some groups also preserved the stalks for winter use by packing them in grease or drying them, but it was most commonly consumed as a spring green and has a nutritional value similar to celery. The seeds were also saved for spicing up winter cooking, and they look kind of like a sunflower seed with wings.

An infusion of the flowers was used as a mosquito repellent, the roots were used to make a yellow dye, and the stalk was dried to make drinking straws for the elderly and flutes for children. Quileute and Makah girls made baskets with the large umbels by twining the rays with seaweed as a form of play.

Though the plant is pretty easy to distinguish with its broad, coarsely toothed, palmately lobed leaves, there's a look-alike that you have to watch out for: Giant Hogweed. This is an invasive plant that is a native of Asia, and silly gardeners thought it would look nice in their landscaping so they planted it here and it escaped. Giant Hogweed causes violent 3rd degree burns, and because of this municipalities do their utmost to get rid of it whenever it pops up. This plant looks similar to the native Cow Parsnip but is enormous: it reaches heights of 3-5 meters. The skin damage from the sap of Giant Hogweed can be permanent, so don't confuse the two.

For having a humble name, Cow Parsnip is a very stately plant with its compound umbels waving in the breeze. Worth a walk in the woods to go admire it.