5 Poisonous Plants to Watch Out for in New Jersey

Recognizing poisonous plants is important to prevent toxic reactions. Which ones should you watch out for in New Jersey?

Exposure to poisonous plants can quickly turn that fun adventure into New Jersey’s great outdoors into, at the least, an itchy mess and, at the worst, a trip to the emergency room. However, poisonous plants don’t just grow in the woods; they can also be found in residential areas, where children and pets may come in contact with them.

Let’s look at five poisonous plants you may encounter while exploring the woods or just taking a walk around your neighborhood or yard.

1. Poison Ivy

Poison ivy is a vine that can be found spread across the ground or climbing trees, rocks, or walls. It has alternate, compound leaves, each containing 3 teardrop-shaped leaflets. On immature plants, the leaflet edges are smooth and become serrated as they mature. Poison ivy stems are light brown and have raised pores. The plant uses aerial roots to climb structures.

The poison ivy plant contains urushiol, which causes an allergic reaction in the form of a rash in most humans. The rash usually develops within 12 hours from exposure and causes itching and burning, which last about one week. 

Urushiol can remain active in dead poison ivy plants for years. You should take precautions when burning brush piles with either living or dead poison ivy because the smoke from burning poison ivy can severely irritate the lungs. 

Poison ivy is widespread across New Jersey, excluding the Pine Barrens. Open regions, wooded areas, and even your backyard are ideal habitats for them.

growing poison ivy in the forest

2. Poison Hemlock

Poison hemlock (Conium maculatum) is a naturalized plant found throughout the United States; it is the plant used in the execution of the Greek philosopher Socrates. Its cousins, eastern and western water hemlock (Cicuta maculata and Cicuta douglasii), are just as deadly and are native to the United States.

Hemlocks are part of the parsnip and wild carrot family and are sometimes confused with wild parsnip. Poison hemlock can be found in ditches, meadows, pastures, and along field edges, basically hiding in plain sight. Its flowers look similar to those of its nonpoisonous relatives, including yarrow and Queen Anne’s lace.

The lacey, fern-like leaves have veins that end at the leaf notch. Its stems are usually green, purple, or green with purple spots or stripes. The plant bears umbrella-shaped, white flowers. It has a long, white taproot that can easily be confused with that of wild parsnip.

Coniine is the toxin found in all parts of the plant. Within one hour of exposure to poison hemlock, humans may experience delirium, nausea, convulsions, abdominal pain, seizures, and vomiting. Death is frequently the result of ingesting one of these plants. Animals that consume poison hemlock usually die within 3 hours from respiratory paralysis. 

Mowing to control the spread of poison hemlock is not recommended in populated areas since toxic particles may be inhaled. Using a broadleaf herbicide (2, 4-D), broad-spectrum herbicide (glyphosate), or a combination of the two may offer the best approach for killing poison hemlock. Careful hand weeding is an option for those not wanting to use pesticides. 

small white flowers of poison hemlock

3. Foxglove

Foxglove (Digitalis purpurea) is a beautiful plant cultivated in many home gardens for aesthetic purposes. The Digitalis genus includes biennials, perennials, and shrubs with the common name foxglove. However, common foxgloves are tall biennial plants that grow well in dry shade. Its bell-shaped flowers are usually purple, but some varieties produce white, creamy yellow, pink, or rose-colored flowers.

Foxglove was once used as an herbal remedy for heart conditions. Modern use of the plant is highly discouraged.

Poisoning occurs when the aerial parts of the plant are ingested. Foxglove contains the poisons: deslanoside, digitoxin, and digitalis glycoside; these can be found in the plant’s stem, flower, leaves, and seed. 

Touching the foxglove plant does not cause a skin reaction, but it is still wise to wear gloves when working the plant. Getting small amounts of toxins in your eyes, mouth, or even an open wound is possible. 

Symptoms include sweating, vomiting, breathing problems, disorientation, hallucinations, possible coma, and even death.

bell shaped flowers blooming in plants stem

4. Monkshood

Monkshood (Aconitum napellus) is a highly toxic plant often used in decorative flower gardens. It has stunning blue to dark purple flowers and grows tall and erect, with fine hairs on its stems. The leaves are dark green and have five to seven angular segments.

Toxins are found in all parts of the plant, particularly the roots, and it is recommended that you wear gloves when handling it. Its alternative name, wolfsbane, refers to when it was used as a quick-acting poison applied on arrowheads for hunting wolves.

Monkshood contains aconitine, one of the most dangerous naturally occurring toxins to humans and animals. Symptoms include numbness and tingling, a slow or fast heart rate, nausea, vomiting, stomach discomfort, and diarrhea. 

Poisoning can happen by touching the plant because the toxin can be absorbed through the skin or mucous membranes.

dark blue flowers growing in the forest

5. Poison Sumac

Poison sumac can grow to be 6 to 25 feet tall. It grows into a large tree-like shrub in areas with consistently damp soil. The plants are hairless and turn light to dark green color in the spring and summer. Its 7 to 13 black-spotted leaflets are oval, with smooth edges and pointy tips. 

In the spring, the poison sumac has bright red stems, which help distinguish it from the nonpoisonous sumacs.

Poison sumac berries are initially green in the spring and remain green most of the summer. The berries are toxic to humans but safe for birds to eat. They are easily distinguished from other berries in the wild because they are not perfectly spherical. 

All parts of the poison sumac plant are toxic, containing the same chemical, urushiol, as poison ivy. The oils stay active even after the plant dies. The symptoms of a poison sumac rash appear 8 to 48 hours after exposure and can last for weeks.

red poison sumac growing in large tree
Phillis Butler
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