Illinois residents are being warned of a poisonous plant growing throughout the state that causes painful blisters and a rash similar to severe burns when touched.

Wild parsnip is spreading across parts of the Midwest, according to health officials, including Iowa and Illinois.

From the outside the wild parsnip – also known as Pastinaca sativa – has lacy, yellow-green heads similar to wildflowers and can look harmless. But the plant secretes an oily sap containing psoralen that causes a severe reaction when it comes in contact with the skin and then is exposed to sunlight, the Iowa Department of Natural Resources reports.

The colorful plant typically flowers from May to July, according IDNR officials, and can grow from 6 inches to 6 feet tall. It is often found in roadside ditches, fields and along bike paths.

Those who come across the plant are urged to avoid using a lawn string trimmer to remove it, as breaking the parsnip tissue will pray a high exposure of the toxin. If found, gloves should be worn for removal.