22 Common Poisonous Plants

Identify what poisonous plants may be present in your backyard using these pictures of common toxic plants in North America. This list will help you to identify vegetation that can be dangerous if touched or consumed. The level of toxicity varies widely but care should be taken before planting or handling the following 22 examples.

WARNING

Always use care and discretion when eradicating toxic plants; the safest option is to hire professionals rather than trying to do the work yourself.

• 01of 22Bittersweet Nightshade The Spruce / David BeaulieuBittersweet nightshade (Solanum dulcamara) is a very common woody weed and is especially dangerous to have around kids because of the brightly colored berries. The highest level of toxicity for humans and animals comes if the berries are consumed but all parts of the plant (bark, leaves, sap) are toxic.¹ The rapidly growing vine is often confused with American bittersweet and Oriental bittersweet plants.
• 02of 22Chinese Lanterns G.N. van der Zee/Getty ImagesRelated to bittersweet nightshade, the Chinese lantern (Physalis alkekengi) plant’s leaves and fruit are toxic.² Commonly grown by crafts enthusiasts, the initial color of the fruit’s husk is green. This color changes to yellow late in the summer and by fall, it is a rich orange. The colorful pods are used in dried floral arrangements and wreaths.
• 03of 22Foxglove The Spruce / Evgeniya VlasovaFoxgloves (Digitalis spp.) are tall, flowering biennials that grow well in a spot with dry shade. They bloom with multiple tubular, often freckled, flowers that form on a spike in colors ranging from purple to white. Resistant to deer and rabbits, if consumed by humans, their flowers, leaves, roots, and stems are among the most toxic specimens commonly grown on landscapes.³
• 04of 22Mountain Laurel David BeaulieuIf you live in the countryside in eastern North America, you may have some mountain laurel (Kalmia latifolia) growing wild in your backyard. Cultivars of mountain laurel are also sold at nurseries, including the beautiful ‘Minuet’ laurel. Mountain laurel, azaleas, and rhododendrons (Rhododendron spp.) belong to the heath family and the bark, sap, leaves, and flowers are toxic.⁴Continue to 5 of 22 below
• 05of 22Castor Bean Guenter Fischer/Getty ImagesCastor bean (Ricinus communis) is a tropical plant widely grown as an annual in northern climates, often as a potted plant for patios, decks, or porches. The leaves, stalk, and seed heads are all attractive. The laxative, castor oil, is derived from castor bean plants, but so is the deadly toxin, ricin.⁵
• 06of 22Yew IMS68/PixabayYew (Taxus spp.) bushes can be grown in sun or shade. This plant’s shade tolerance gives landscape designers an important option in challenging areas. But its fleshy, bright-red berries contain a toxic seed. The needle-like leaves are toxic to humans and animals.⁶
• 07of 22Poison Sumac The Spruce / David BeaulieuBoth the leaves and berries of poison sumac (Toxicodendron vernix) are toxic.⁷ The poison sumac gives all sumac shrubs a bad name, even though most are quite harmless and beautiful in fall. Poison sumac has leaves made up of seven to 13 leaflets (always an odd number), a red stem, and white odd-shaped berries.
• 08of 22Poison Ivy Ed Reschke/Getty ImagesPoison ivy’s  (Toxicodendron radicans) toxic quality comes from an oil called urushiol. While the leaves are the most toxic element of the plant, contact with any part (even when bare of foliage) should be avoided to prevent a reaction. This also means you should not burn the plant because the smoke will also cause a reaction.⁷Continue to 9 of 22 below
• 09of 22Easter Lily The Spruce / David BeaulieuGardeners in northern climates cannot expect Easter lilies (Lilium longiflorum) to bloom outdoors much earlier than July when most of the other popular lilies flower. (The ones you buy at the store have been forced to bloom for the holiday.) While the sap of the stems and leaves can be toxic to humans, Easter lilies and ‘Stargazer’ lilies are more problematic as they are very toxic for cats.⁸
• 10of 22Stinging Nettles Judith Haeusler/Getty ImagesLike poison sumac and poison ivy, stinging nettles (Urtica spp.), as its name suggests, is not a plant you want to brush up against when working out in the yard.⁹ Don’t confuse stinging nettles with dead nettles, a perennial used as a ground cover in shady areas.
• 11of 22Yellow Dock byrev/PixabayThe ASPCA lists dock (Rumex sp.) as toxic to dogs.¹⁰ The toxicity to humans is low. Dock (also known as sorrel) is easy to identify late in the season.¹¹ The mature flower head of a yellow dock plant looks like coffee grounds after its blooms have dried and assumed a brown color.
• 12of 22Lantana sylviaestock/PixabayLantana (Lantana camara) bears colorful flower clusters and is commonly used as an annual by gardeners in cold climates in hanging pots. Growers in warmer climates are familiar with lantana as a shrub, where this vigorous grower may even be invasive. But its invasiveness is not the only issue that comes with growing lantana: the berries, leaves, and sap are toxic.¹²Continue to 13 of 22 below
• 13of 22Lily-Of-The-Valley Happynut/PixabayLily-of-the-valley (Convallaria majalis) is a traditional wedding flower. Its flowers are bell-shaped, fragrant, and white. From a landscaping perspective, lily-of-the-valley can become a problem because it is invasive. Despite its delicate and romantic appearance, lily-of-the-valley is toxic in large amounts.¹³
• 14of 22White Baneberry The Spruce / David BeaulieuWhenever you see the word “bane” in a plant name, chances are excellent that the plant is toxic.¹⁴ Baneberry (Actaea), an herbaceous perennial that belongs to the buttercup family, comes in both a red and a white form. If its toxicity is not enough to scare you, stare into the spooky “doll’s eyes” of the white form.
• 15of 22Tansy sola deo gloria/Getty ImagesCommon tansy (Tanacetum vulgare) was once a much-valued herb that has now fallen from grace. It is a perennial that is often grown simply for its golden flowers, which are numerous and look like cute little buttons. When ingested, it’s toxic to people and animals, and especially livestock.¹⁵ It’s common to mistake tansy and equally toxic tansy ragwort (Jacobaea vulgaris) for each other since they look similar.¹⁶
• 16of 22Poison Oak  Darren415 / Getty ImagesPoison oak (Toxicodendron diversilobum), like poison ivy, has three leaves, making it easy to identify. The leaves are also shaped like those of an oak tree. The leaves redden in the autumn, and then the plant produces white berries. Though it’s not the easiest toxic plant to eradicate, the best method is to pull it out manually by its roots while wearing protective gear or using herbicides while the plant is in active growth mode. If touched, a severe skin rash typically develops.¹⁷Continue to 17 of 22 below
• 17of 22Oleander Ursula Alter / Getty ImagesOleander (Nerium oleander) is an easy-growing, pretty, and fragrant flowering shrub used for hedging and other places in the landscape. It’s also highly toxic when touched or eaten by humans and animals.¹⁸¹⁹ Plant oleander far away from gardens or areas of play that children or pets may use. Even when planting this bush, wear protective clothing and gloves to avoid direct contact.
• 18of 22Mistletoe Jurg Waldmeier / Getty ImagesThe many types of mistletoe lead a double life. It’s used as a traditional holiday decoration and it’s also a parasitic broadleaf evergreen that attaches to trees and shrubs, growing in unsightly balls.Though mistletoe (Phoradendron spp., Viscum spp., Arceuthobium spp.), in general, is thought of as a festive plant, some types are more toxic to humans and animals than others when ingested.²⁰ For example, American mistletoe (Phoradendron serotinum) may not be quite as toxic as European mistletoe (Viscum album). ²¹ To be safe, keep any type of mistletoe out of reach from children and pets.
• 19of 22Jimsonweed Jared Quentin / Getty ImagesJimsonweed (Datura stramonium) is highly toxic to both humans and animals when it’s ingested.²² The most distinguishing part about this nightshade family plant is its thick purple stems, large and attractive trumpet-shaped white or purple flowers, and a disagreeable odor that smells something like stinky feet.²³ The plant has shallow roots and can easily be removed by weeding.
• 20of 22Poison Hemlock The Spruce / K. DavePoison hemlock (Conium maculatum) is not only toxic to humans and animals if ingested in small amounts, but it is also classified as an invasive plant.²⁴²⁵ It’s not easy to identify because its appearance changes and other non-toxic plants look similar. In its first year, it will produce white umbrella-like flowers resembling Queen Anne’s lace. But the easiest way to identify this plant is in its second year when the hollow, hairless stems have telltale reddish-purple streaks and spots.²⁶Seedlings are easy to remove but an infestation takes more diligence by mowing and using chemicals to weaken the plants. Never burn or compost this plant. It should always be properly disposed of in a sealed garbage container.Continue to 21 of 22 below
• 21of 22Wild Parsnip KathrynSK / Getty ImagesWild parsnip (Pastinaca sativa) is a tall plant with characteristic yellow flowers and leaves that appear celery-like. Oftentimes wild parsnip grows among poison hemlock, creating a sea of yellow and white umbrella-like flowers. Wild parsnip should never be touched as it is highly toxic to humans and animals.²⁷²⁸
• 22of 22Giant Hogweed The Spruce / K. DaveGiant hogweed (Heracleum mantegazzianum) grows tall to about 15 or 20 feet in height and often produces clusters of white flowers that resemble Queen Anne’s lace. However, giant hogweed looks similar to poison hemlock in that it will have stems with purple spotting but it will also have some hair growth. The leaves of giant hogweed look very different from poison hemlock; they are not lacy but are large and deeply incised. The plant is extremely toxic to touch for both humans and animals.²⁹³⁰

What to Do If You Touch a Poisonous Plant

Here’s what to do if you touch a toxic plant:³¹

• Immediately rinse your skin with rubbing alcohol, poison plant wash, or a degreasing dishwashing soap or detergent, and lots of water. Scrub under your nails using a brush. Keep rinsing and do it frequently so none of the solutions you are using dry on your skin or spread the urushiol (oily resin in poisonous plants).
• Apply wet compresses, calamine lotion, or hydrocortisone cream to the skin to reduce itching and blistering.
• Seek immediate medical attention if you have a severe allergic reaction, difficulty breathing, or swelling on your body or face.

FAQ

• What plant is the most toxic to humans?Belladonna (Atropa belladonna) is considered one of the most toxic plants to humans and animals, mostly because of its sweet-tasting fruit. It is not the most common plant, thankfully. In the United States, belladonna has been found in only a few states, growing in wastelands and areas with disturbed soil, such as dumps, quarries, and roadsides. Monkshood is one of the most dangerously toxic plants found in garden landscapes.³² It is toxic if ingested and may be fatal to humans and pets. Gardeners are advised to wear gloves when handling it in any way. Foxglove, listed above, is another plant noted to be most toxic to humans.
• What are some common characteristics used to identify poisonous plants?One common characteristic used to identify poisonous plants, like poison ivy and poison oak, is the number of leaves. These plants have three leaves budding from a stem. However, the characteristics of other poisonous plants can vary. It helps to identify the poisonous plants common during each season in your area.³³
• What is a common plant that is toxic to pets?Many common plants are toxic for pets, including bulbs like lilies, autumn crocus, tulips, hyacinths, and daffodils in addition to shrubs like oleander. and wildflowers like lily of the valley. Common houseplants toxic to pets include snake, jade, pothos, philodendrons, and dumb cane plants. This is only a short list of the many common plants that are not safe for pets.