Field work activities can also increase our chances for exposure to poisonous plants. Here we provide some tips to avoid common poisonous plants in North America that can cause skin reactions. Keep in mind that you should never consume plants, mushrooms, or berries in the field if have not been trained in their identification.
Explore the tabs below to learn more about some of the poisonous plants found in North America. These are all plants that can irritate the skin. Plants that poison through ingestion are not covered here. It is not advisable to consume any plants or fungi of which you are not familiar in case they are poisonous.
Range: All U.S. states east of the Rocky Mountains
Inhabits: Wooded areas, especially along tree line breaks. Also known to grow in open fields
“Leaves of three, Let it be” is a popular saying that helps people identify this noxious plant. Despite being called a Poison Ivy, this plant is not a true Ivy. The leaves range from light green to a reddish color depending on the season. Contact with the parts of this plant causes most people’s skin to blister and become red and itchy.
Range: Throughout the U.S. and Canada
Inhabits: Usually occurs in moist sites along streams, open forests, ditches and woodland clearings.
This plant is covered by tiny hairs that act like hypodermic needles. Upon contact these hairs inject irritants into your skin, causing blisters and a burning, itchy sensation. Not something you want to brush up against.
Often seen growing in similar habitats to stinging nettle, rubbing jewelweed sap on your skin can help sooth the pain and discomfort from stinging nettles and poison ivy.
Range: Eastern U.S. and Canada
Inhabits: Grows exclusively in swamps, bogs and wetlands.
Poison Sumac grows into a small tree. Contact with this nasty plant will result in a reaction similar to the aforementioned Poison Ivy and Poison Oak. This is because all three produce an oily allergenic substance called Urushiol.
Range: Western North America
Inhabits: Conifer and mixed broadleaf forests, woodlands and grasslands
It is very common in the Pacific Northwest of the U.S. It can be identified by lobed, oak-like leaves that grow in groups of 3 and range from green to bright red depending on the season. The oils present on Poison Oak leaves or branches will cause an itchy reaction in most people who come in contact with them. If you are hiking the Pacific Coast Trail or anywhere west of the Rockies, you’ll want to be on the lookout for this plant.
Range: Parts of Florida and the Caribbean
Inhabits: Primarily found in coastal regions
The University of Florida reports that the Manchineel was called the “arbol de la muerte” meaning tree of death. They were referring to pomes which grow 1-2 inches and look a lot like an apple. However, be warned, all parts of this tree are extremely toxic and will cause burning blisters on contact. Even a quick brush against its bark or standing under the tree without contacting it at all can make for a very bad day. It is also reported that ingesting any part of this tree or it’s fruit can be lethal. The tree may look innocent, but avoid it at all costs!
Avoiding Adverse Effects from Poisonous Plants
- Learn to recognize and avoid poisonous plants common to your work area.
- Wear long pants and long-sleeved shirts to eliminate or minimize exposures.
- Carry hydrocortisone cream or other itch relievers in your first aid kit.
- Never ingest plants, berries, or fungi found in the field unless you are sure of their identity.