A toxic weed that causes severe rashes is spreading in parts of the Midwest

Large patches of a poisonous weed are popping up across certain U.S. states, causing anyone who comes in contact with it to develop a burning, itchy rash that lands them in the Emergency Room.

Wild parsnip grows in nearly all 50 states, but its recent growth in Iowa and Illinois has led the states to issue health warnings, reports Fox59.

Most people don't realize that they have been exposed to the poisonous plant, and end up developing blisters and welts within hours.

People have been encountering it while hiking, gardening and biking along trails.

The plant's effects can last weeks, and its scars can stay on skin for years.

Additionally, the plant's chemicals can cause a reaction in sunlight that breaks down cells and tissues.

Wendy Prusha, of Iowa, was exposed to Wild Parsnip while gardening, according to KCCI8. She noticed it growing near a creek outside her house, and tried to get rid of the weed in what she thought was a simple gardening task.

However, the exposure caused a severe rash to develop, which ended up sending Prusha to the hospital.

"It's a constant burning (feeling). It just bubbled up overnight," Prusha told KCCI8. "The oils sit on your skin. It eats away your skin."

The plant doesn't appear to be dangerous at first glance, though. It can grow to be four or five feet tall, and looks like a harmless wildflower, with a yellow and green appearance.

But "it's very dangerous and very harmful," according to Prusha.