Poisonous Plants

Poisonous Plants

This page contains information on how to identify and avoid poisonous plants in an emergency situation. Exampels are plants that are poisonous when touched such as poison ivy, poison oak, and poison sumac, and plants that are poisonous when ingested such as Castor Bean, Oleander, Rosary Pea, Water Hemlock, Poison Hemlock. You will also find out how to identify the symptoms and also preventions and finally a list of the most poisonous plants.
Plants basically poison on contact, through ingestion, by absorption, or by inhalation. They cause painful skin irritations upon contact, they cause internal poisoning when eaten, and they poison through skin absorption or inhalation in to the respiratory system. Positive identification of edible plants will eliminate the danger of accidental poisoning. There is no room for experimentation where plants are concerned, especially in unfamiliar territory.

Identifying Poisonous Plants

Poison ivy, poison oak, and poison sumac release an oil, urushiol, when the leaf or other plant parts are bruised, damaged, or burned. When the oil gets on the skin an allergic reaction, referred to as contact dermatitis, occurs in most exposed people as an itchy red rash with bumps or blisters. When exposed to 50 micrograms of urushiol, an amount that is less than one grain of table salt, 80 to 90 percent of adults will develop a rash. The rash, depending upon where it occurs and how broadly it is spread, may significantly impede or prevent a person from performing some daily tasts. Although over-the-counter topical medications may relieve symptoms for most people, immediate medical attention may be required for severe reactions, particularly when exposed to the smoke from burning these poisonous plants. Burning these poisonous plants can be very dangerous because the allergens can be inhaled, causing lung irritation.

Poisonous plants that cause contact dermatitis are: Cowhage. Poison ivy. Poison oak. Poison sumac. Rengas tree. Trumpet vine.

The following plants can cause ingestion poisoning if eaten: Castor bean. Chinaberry. Death camas. Lantana. Manchineel. Oleander. Pangi. Physic nut. Poison and water hemlocks. Rosary pea. Strychnine tree.

People who spend more time outdoors may be exposed to poisonous plants. Forestry workers and firefighters who battle forest fires are at additional risk because they could potentially develop rashes and lung irritation from contact with damaged or burning poisonous plants. It is important for individuals to train themselves about their risk of exposure to poisonous plants, how they can prevent exposures and protect themselves, and what they should do if they come in contact with these plants.

To avoid potentially poisonous plants, stay away from any wild or unknown plants that have:

  • Milky or discolored sap.
  • Beans, bulbs, or seeds inside pods.
  • A bitter or soapy taste.
  • Spines, fine hairs, or thorns.
  • Foliage that resembles dill, carrot, parsnip, or parsley.
  • An almond scent in woody parts and leaves.
  • Grain heads with pink, purplish, or black spurs.
  • A three-leafed growth pattern.

Location of Poisonous Plants

One or more of the most common poisonous plant species are found throughout the United States (except Alaska and Hawaii). These plants can be found in forests, fields, wetlands and along streams, road sides, and even in urban environments, such as, parks and backyards.

  • Poison Ivy: Across the United States, except California, Alaska, and Hawaii.
  • Poison Oak: Primarily the Southeast and West Coast.
  • Poison Sumac: Abundant along the Mississippi River and boggy areas of the Southeast.

Plant Identification

The old saying "Leaves of three, Let it be!" is a helpful reminder for identifying poison ivy and oak, but not poison sumac which usually has clusters of 7-13 leaves. Even poison ivy and poison oak may have more than three leaves and their form may vary greatly depending upon the exact species encountered, the local environment, and the season. Being able to identify local varieties of these poisonous plants throughout the seasons and differentiating them from common nonpoisonous look-a-likes are the major keys to avoiding exposure.

Poison Ivy

Poison Ivy
  • Eastern poison ivy is typically a hairy, ropelike vine with three shiny green (or red in the fall) leaves budding from one small stem.
  • Western poison ivy is typically a low shrub with three leaves that does not form a climbing vine.
  • May have yellow or green flowers and white to green-yellow or amber berries.

Poison Oak

Poison Oak
  • Typically a shrub with leaves of three, similar to poison ivy
  • Pacific poison oak may be vine-like
  • May have yellow or green flowers and clusters of green-yellow or white berries
  • Poison ivy and oak can be found in almost any habitat in North America.

Poison Sumac

Poison Sumac
  • Woody shrub that has stems that contain 7-13 leaves arranged in pairs
  • May have glossy, pale yellow, or cream-colored berries
  • All parts can cause serious contact dermatitis at all times of the year.
  • Poison sumac grows only in wet, acid swamps in North America.

Below is a list of poisonous plants which can cause ingestion poisoning if eaten:

Castor Bean

Poison Ivy

The castor bean is a semiwoody plant with large, alternate, starlike leaves that grows as a tree in tropical regions and as an annual in temperate regions. Its flowers are very small and inconspicuous. Its fruits grow in clusters at the tops of the plants. All parts of the plant are very poisonous to eat. The seeds are large and may be mistaken for a beanlike food. Castor bean is found in all tropical regions and has been introduced to temperate regions.


Poison Ivy

This shrub or small tree grows to about 9 meters (27 feet), with alternate, very straight, dark green leaves. Its flowers may be white, yellow, red, pink, or intermediate colors. Its fruit is a brown, podlike structure with many small seeds. All parts of the plant are very poisonous. Do not use the wood for cooking; it gives off poisonous fumes that can poison food. This native of the Mediterranean area is now grown as an ornamental in tropical and temperate regions.

Rosary Pea (Crab's Eyes)

Poison Ivy

This plant is a vine with alternate compound leaves, light purple flowers, and beautiful seeds that are red and black. This plant is one of the most dangerous plants. One seed may contain enough poison to kill an adult. This is a common weed in parts of Africa, southern Florida, Hawaii, Guam, the Caribbean, and Central and South America.

Poison Hemlock (Fool's Parsley)

Poison Ivy

This biennial herb may grow to 2.5 meters (8 feet) high. The smooth, hollow stem may or may not be purple or red striped or mottled. Its white flowers are small and grow in small groups that tend to form flat umbels. Its long, turniplike taproot is solid. This plant is very poisonous, and even a very small amount may cause death. This plant is easy to confuse with wild carrot or Queen Anne's lace, especially in its first stage of growth. Wild carrot or Queen Anne's lace has hairy leaves and stems and smells like carrot. Poison hemlock does not. Habitat and Distribution: Poison hemlock grows in wet or moist ground like swamps, wet meadows, stream banks, and ditches. Native to Eurasia, it has been introduced to the United States and Canada.

Water Hemlock (Spotted Cowbane)

Poison Ivy

This perennial herb may grow to 1.8 meters (6 feet) high. The stem is hollow and sectioned off like bamboo. It may or may not be purple or red striped or mottled. Its flowers are small, white, and grow in groups that tend to form flat umbels. Its roots may have hollow air chambers and, when cut, may produce drops of yellow oil. This plant is very poisonous and even a very small amount of this plant may cause death. Its roots have been mistaken for parsnips. Habitat and Distribution: Water hemlock grows in wet or moist ground like swamps, wet meadows, stream banks, and ditches throughout the Unites States and Canada.

The following is a list of some of the poisonous plants, in an alphabetical order: Amaryllis, Azalea, Bird of Paradise, Black Nightshade, Buttercup, Butterfly Weed, Calla Lily, Calamondin, Caladium, Carnation, Carolina Jasmine, Castor Bean, Chinaberry, Chinese Tallow, Christmas Berry, Cyclamen, Daffodil, Daisy, Daphne, Deadly Nightshade, Devils Ivy, Dieffenbachia, Dumbcane, Elderberry, Elephant Ears, English Holly/Ivy, Eucalyptus, Eyebane, Foxglove, Golden Chain, Holly Berry, Horsechestnut, Hyacinth, Hydrangea Blossom, Iris, Jack-in-the-Pulpit, Jerusalem Cherry, Jimson Weed, Juniper, Lantana, Larkspur, Laurel, Lily-of-the-Valley, May Apple, Mistletoe, Moonflower, Morning Glory, Needlepoint Ivy, Oleander, Oxalis, Peace Lily, Philodendron, Poison Ivy, Poison Oak, Poison Sumac, Pokeweed, Potato Plant, Pothos, Pyracantha, Rhododendron, Rhubarb, Sand Begonia, Skunk Cabbage, Spathe Flower, String of Pearls, Tomato Leaves, Tulips, Violet Seeds, Water Hemlock, Wild Carrots, Wild Cucumber, Wild, Parsnip, Wild Peas, Wisteria, Yew.


Individuals may become exposed to urushiol through:

  • Direct contact with the plant
  • Indirect contact, such as touching tools, livestock, or clothing that have urushiol on them
  • Inhalation of particles containing urushiol from burning plants


Signs or symptoms associated with dermal contact with poisonous plants may include:

  • Red rash within a few days of contact
  • Possible bumps, patches, streaking, or weeping blisters (blister fluids are not contagious)
  • Swelling
  • Itching


Individuals can prevent contact with poisonous plants by taking these steps:

  • Wear long sleeves, long pants, boots, and gloves.
  • Wash exposed clothing separately in hot water with detergent.
  • Barrier skin creams, such as a lotion containing bentoquatum, may offer some protection before contact.
  • Barrier creams should be washed off and reapplied twice a day.
  • After use, clean tools with rubbing alcohol (isopropanol or isopropyl alcohol) or soap and lots of water. Urushiol can remain active on the surface of objects for up to 5 years.
  • Wear disposable gloves during this process.
  • Do not burn plants that may be poison ivy, poison oak, or poison sumac.
  • Inhaling smoke from burning plants can cause severe allergic respiratory problems.

First Aid from Poisonous Plants

People who have come in contact with poisonous plants should do the following. Note that this doesn't apply to poisonous plants that were eaten:

  • Immediately rinse skin with rubbing alcohol, specialized poison plant washes, degreasing soap (such as dishwashing soap) or detergent, and lots of water.
  • Rinse frequently so that wash solutions do not dry on the skin and further spread the urushiol.
  • Scrub under nails with a brush.
  • Apply wet compresses, calamine lotion, or hydrocortisone cream to the skin to reduce itching and blistering.
  • Follow the directions on any creams and lotions. Do not apply to broken skin, such as open blisters.
  • Oatmeal baths may relieve itching.
  • An antihistamine such as diphenhydramine (Benadryl) can be taken to help relieve itching.
  • Follow directions on the package.
  • Drowsiness may occur.
  • If children come in contact with work clothing contaminated with urushiol, a pediatrician should be contacted to determine appropriate dosage.
  • In severe cases or if the rash is on the face or genitals, seek professional medical attention.
  • Call 911 or go to a hospital emergency room if the worker is suffering a severe allergic reaction, such as swelling or difficulty breathing, or has had a severe reaction in the past.


More information: We hope this page was helpful and provided you with some information on how to identify and avoid poisonous plants. Check out our main page for more survival scenarios here Survival Guide, knowledge is light, and knowledge can save your life. Make sure you do your best to know what to do in a survival situation and then hope for the best.


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