Hogweed is an invasive plant found throughout North America, particularly along the Atlantic coast. Its sap can cause severe blisters and even blindness if it contacts the eyes due to a chemical reaction triggered by sunlight.
Native to tropical South America and southern North America, the manchineel tree is highly toxic. Its sap causes blistering upon contact, and its fruits are fatal if ingested. It is considered the world's most dangerous tree.
Poison ivy is notorious for causing skin irritation through its urushiol oil. The plant is common in the South and is easily identified by its three-leaved clusters.
Poison oak, similar to poison ivy, contains urushiol oil, which causes skin irritation. It can be identified by its oak-like leaves and can appear as a shrub or vine.
Found in wetland areas, poison sumac causes a painful rash through contact. It is identified by its pinnately compound leaves and green berries, unlike the harmless red-berried sumac.
Stinging nettle is covered in tiny hairs that release irritants when touched, causing a stinging sensation and possible inflammation.
This vine has clusters of purple flowers and red berries, both toxic to pets and humans. It was introduced to North America as an ornamental plant.
A member of the carrot family, poison hemlock is extremely poisonous. It resembles parsley but is dangerous if consumed, and its toxins can be absorbed through the skin.