Here are 3 types of poisonous plants to look out for:
1) Poison Oak. This deciduous plant can grow in the form of a shrub or climbing vine on oak tree trunks, and is most commonly found in places that are less than 4000 feet in elevation. There are 2 species of poison oak: Atlantic poison oak, which is primarily found in the southeast US; and Western poison oak, which is found along the Pacific coast. These 2 species are closely related and look very similar.
You can identify poison oak by its trifoliate leaf structure – 3 leaflets attached to a node on the stem. Since many other plants also have this structure, you should specifically look for projections on the leaf that give the edge a wavy appearance. The leaves will also be glossy on their top side and matte on their lower side. They are usually about 6 inches long, and will be bright green in the spring, yellow-green/pinkish in the summer, and yellow/dark brown in the autumn.
The stems will have tiny hairs on them, giving them a fuzzy texture. But don’t touch them! They also contain the urushiol, an oily allergen that causes skin rashes on contact, which is found in the leaves.
In the spring, poison oak produces small light yellow-green flowers, about half an inch in diameter, that grow in clusters. Greenish-white berries, also in clusters, grow near the flowers.
2) Poison Ivy. Like poison oak, poison ivy can be found all across the US. However, elevation is no issue for this poisonous plant. It grows in the woods, in fields, backyards, sunny places, everywhere. It most commonly tends to grow along fences and walls as a vine, though it can also grow as a bush or a single plant.
Poison Ivy can also be identified by its trifoliate leaf structure. However, it looks a bit different from poison oak. The projections are pointier rather than wavy, and the middle of the 3 leaves is a little bigger than the 2 lateral leaves. The center leaf also has its own little stem, while the 2 side leaves grow directly from the vine. They maintain a bright to dark green color that can either be waxy on top, lighter and fuzzier on the bottom, or not shiny at all.
Poison Ivy plants also grow berries that are white or cream that grow in clusters around the stems.
3)Poison Sumac. This small tree is usually found in the eastern US and Canada, and is considered to be the most toxic of all poisonous plants. The reason for this is that the urushiol that poison sumac contains is far more virulent than poison oak or poison ivy. It grows exclusively in very wet ground, usually in swamps or marshes. When fully matured, poison sumac trees can stand 6-20 feet high.
You can identify poison sumac by its pinnate leaf structure – each stem contains 2 parallel rows of leaves on either side, with a single leaf at the end. The stems will contain between 7 and 13 leaves. The leaves, which range between 2-4 inches in length, are oval shaped and taper at the tip into a fine point. They are usually bright green in the warmer months and turn bright red in the fall. Unlike poison oak and poison ivy, poison sumac has a smooth, matte texture that is usually hairless but sometimes has a fuzzy layer on the bottom.
White or greenish-white berries grow in clusters on the stems, very similar to poison oak and poison ivy.
How to Treat Poison Oak, Ivy, and Sumac:
If you accidentally brush up against any of these 3 poisonous plants during your hike in the woods, immediately wash the affected area with cool water and a soap that does not contain any oils. Make sure to scrub your fingers and hands to make sure all plant oils are washed off. Next, rub the area with rubbing alcohol, which will dissolve the urushiol. Rinse with cool water immediately afterwards. Apply a cold compress or icepack for 10-15 minutes and allow to air dry – don’t rub the affected area with a towel! Next, take a lukewarm bath, adding oatmeal or aluminum acetate to soothe your skin. After the bath, apply calamine or hydrocortisone lotion to relieve the itching a bit. If the topical creams don’t work, take antihistamines.