Stinging nettle has tiny hairs on its leaves and stems that release irritating chemicals when touched, causing a stinging sensation and skin irritation.
Poison ivy contains an oily resin called urushiol, which can cause an itchy and blistering rash in many people who come into contact with it.
Also known as the stinging tree, this plant native to Australia has fine hairs on its leaves and stems that can cause excruciating pain when touched.
Bull nettle is a plant found in the southern United States. Its leaves and stems are covered in stinging hairs that can cause intense burning and irritation.
Giant hogweed is a tall plant with sap that contains chemicals that can cause severe skin irritation, blistering, and even burns when exposed to sunlight.
Poison oak, similar to poison ivy, contains urushiol and can cause a painful and itchy rash upon contact.
The hairy leaves and stems of the tree manzanita plant can cause skin irritation and painful rashes in some individuals.
While cacti are known for their spines, some species also have tiny hair-like spines called glochids that are extremely irritating and can cause pain and skin irritation upon contact.