Cow parsnip

About

A big native wildflower of moist meadows and stream banks, valued by pollinators and wildlife. Its sap can burn skin in sunlight, and it is the plant most often mistaken for invasive giant hogweed.

Also called American cow parsnip, common cowparsnip, American hogweed, Indian celery, pushki

How to identify it

Look for

Plants stand 4 to 10 feet tall with large leaves split into three broad, lobed, toothed leaflets. Stems are grooved, hollow and hairy, sometimes with purple splotches, and smell strong when crushed. Flat white flower clusters are about 6 to 12 inches across.

Look-alikes

Giant hogweed is much larger (7 to 14 feet), with stems 2 to 4 inches thick, coarse hairs, deeply cut leaves and flower heads up to 2½ feet wide. Poison hemlock has smooth, spotted stems and fern-like leaves.

Where it grows

Moist meadows, stream banks, floodplains, woodland openings and shady yard edges.

When

Leaves come up in spring, and it blooms from late spring into summer (about April to August depending on the region), then sets flat seeds.

How it spreads

Spreads by seed and comes back each year from a stout taproot.

Most common in

What to do, gentlest first

Protect yourself first. Weed killers are a last step; always read and follow the label.

1. Let it be where it's welcome Prevent

   It's a native wildflower, so leave it in wild corners and along streams. Wear protective clothing when working near it.

   Make sure it isn't giant hogweed; if unsure, report it.

2. Pull or dig unwanted plants By hand

   Remove unwanted plants by hand or dig the taproot, ideally before they set seed.

   Wear gloves and eye protection, and wash exposed skin right away with soap and water.

Uses, wildlife and pets

For wildlife

Bees, wasps and butterflies use the easy-to-reach nectar and pollen, it hosts swallowtail caterpillars, and deer, elk, moose and bears eat it.

Pets

Toxic to dogs, cats and horses (ASPCA); the sap can cause sunburn-like skin damage.