Certified Arborist Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer identifies specific plants known for causing severe skin rashes due to their toxic properties. Poison ivy, poison sumac, and poison oak all contain an oily resin called urushiol, which triggers allergic reactions in many people, resulting in itching, redness, and blistering upon contact. Giant hogweed, on the other hand, contains phototoxic sap that can lead to severe skin burns when exposed to sunlight.

These plants are notorious for their ability to cause skin irritations and have been well-documented in botanical and medical literature as hazardous to humans. Knowledge about these plants is vital for anyone working outdoors or in landscaping, as avoiding contact can prevent painful and distressing reactions.

The other options do not pertain to plants that cause skin rashes. Their context does not relate to the question about plants and their potential effects on skin, thereby reinforcing the correctness of the choice that lists the well-known rash-inducing plants.