A hike through the woods or mountains can be an enjoyable way to spend a summer day, but if you come across certain types of poisonous plants that cause itching upon contact, your pleasant afternoon may be cut short. These plants may look harmless, but they can make your skin itch, swell, turn red and develop painful blisters. Being able to identify these irritating plants will help you avoid them wherever they may grow.
One of the most common plants that cause itching is poison ivy. Individuals who come into contact with poison ivy generally experience itching, swelling and redness across the skin. In serious cases, blisters also may develop. This is due to the poisonous sap, urushiol, which is found in the leaves, fruit, stems and roots of the plant. Poison ivy may be found throughout North America, but is found in larger concentrations in the eastern and central United States. It typically grows in fields, forests, river banks and rocky canyons, and may crawl or climb up tree trunks and other surfaces. Poison ivy plants consist of clusters of three pointed leaves. The middle leaf is usually longer than those on either side, and the leaves may be smooth or jagged along the edge. In the spring, the leaves appear reddish but turn green during the summer. In the fall, they turn varying shades of red, orange and yellow. During the summer, small green flowers bloom on the plant's main stem as well. Poisonous berries develop near the end of summer, which grow in clusters and have a white, waxy appearance.
Like poison ivy, poison sumac may cause itching, redness, swelling and blisters when individuals come into contact with the plant. Poison sumac grows across North America, though it tends to thrive in the eastern portion where there are swampy areas. The plant grows on small trees or shrubs with orange, brown or grey twigs. The leaves typically grow as single leaflets and may have fluffy hairs along the edge. Poison sumac also may grow small hard berries, which are grouped in clusters that hang from the branches and may be white, yellow or grey in colour. There are also harmless sumac plants, which can be identified by their red berries.
The effects of stinging nettle are not felt as long as those of poison ivy, but the plant can still cause a great deal of discomfort for individuals who come into contact with it. Stinging nettle contain small, prickly hairs that catch on the skin and cause itching and stinging. The plant grows all over the world, but thrives especially well in regions with nitrogen-rich soil. Stinging nettle contain heart-shaped leaves that are tapered at the end and also may have yellow or pink flowers. The plant is covered with small, stiff hairs, which contain formic acid, the chemical substance that stings the skin and causes itching upon contact.