Know about Poisonous Plants - for the Health and Well Being of Your Family
Written by Keppy Arnoldsen
With the summer season upon us, and outdoor activities at their peak, it is important to know the poisonous plants present in our environment. It could affect the well-being of your family. Deaths from poisoning are not very common today, but occasional fatalities from consuming poisonous plants and mushrooms still occur. Recognition and identification of those plants can mean the difference between life and death.
The first step toward that goal is knowledge, i.e., which plants are harmful if eaten. The following lists of common poisonous plants will be helpful toward that goal. The second step is recognition. While the recognition is difficult to teach in the space of this article, workshops on poisonous plant identification will be available in the future at our new facility – Earthen Art. You can also purchase field guides to help in plant identification or use the internet to educate yourself about the plants on this list.
The following plants have been reported and documented to produce serious or life-threatening poisoning in humans. The threat is even worse for young children because of their lower body weight and reduced immune systems. This list is not extensive or complete, but it represents many plants worth knowing about. My notes about some of the plants are included as well.
First listed are the native plants (indigenous to Pennsylvania) and then cultivated plants (separated into annuals and perennials), followed by shrubs and trees (both native and cultivated). Lists are alphabetized within each category by common name which is followed by the Latin name in parentheses.
Native Plants:
Baneberry, Dolls Eyes, White Cohosh, Snakeberry (Actaea species) – while not deadly in the U.S., a handful of berries will cause severe abdominal problems for hours; Bleeding Heart, Squirrel Corn, Dutchman’s Breeches (Dicentra species) – all parts are poisonous; Bloodroot (Sanquinaria canadensi) – red latex can cause death; Bouncing Bet (Saponaria species) – plants and especially seeds are toxic; Buttercup or Crowfoot (Ranunculus species) – leaves and flowers are toxic and can cause death; Jimson Weed (Datura stramonium); Mayapple or Mandrake (Podophylum peltatum) – some parts are poisonous, and it is easy to identify due to its large umbrella-like leaf; Nightshade or Horse Nettle (Solanum species, including S. nigrum, referred to as deadly nightshade) – these members of the potato family are quite harmful, and deadly nightshade can kill by paralysis; Pokeweed (Phytolacca Americana) – just because the young leaves are eaten (as noted in the song “Poke Salad Annie”), does not mean this plant is safe! In fact this plant has poisonous berries, and one berry can kill a child; Poison Hemlock (Conium maculatum) – extremely poisonous, in even small amounts; Ragwort or Groundsel (Senecio species); Snakerootor White Snakeroot (Eupatorium rugosum) – toxic parts are leaves and stems, which can be fatal; Water Hemlock (Cicuta maculata) – this plant has a yellowish oily liquid in the stems and roots, and a piece of root the size of a pea can be fatal.
Cultivated Plants:
The following list includes plants that are not native to Pennsylvania, but that might be found in gardens as ornamental plants. Some of them cause serious illness, while others cause less severe problems, from skin rashes to severe vomiting or diarrhea. Some of these plants cause serious symptoms when eaten in large quantities and can lead to death.
Annual landscape plants (those you replant each year that don’t “overwinter” here):
Angel’s Trumpet and Red Angel’s Trumpet (Brugmansia arborea and B. sanguinea); Lantana (Lantana camara); Pigweed (Amaranthus species); Sweat Pea (Lathyrus species).
Perennial landscape plants (those which survive our cold winters here):
Crown Vetch (Coronilla varia) – planted extensively along roadways to stabilize banks; Delphiniums and Larkspurs (Delphinium elatum and other species); Foxglove (Digitalis purpurea); Lobelia (Lobelia species); – these four spikey-flowered plants are commonly planted as flowers in our gardens; Lenton rose or Christmas rose (Helleborus niger) – planted as a flower in our gardens, it blooms very early in the year when snow can still be seen on the ground; Lily of the Valley (Convallaria majalis) – a very common garden plant with little white bells; Lupine (Lupinus species) – foliage and seeds are toxic; Monkshood (Aconitum species) – not as common in our flower gardens but still planted by some; it has a tall stalk of purplish large bells on a spike; Wisteria (Wisteria species) – planted as vines on arbors and trellises.
Shrubs (both planted and native):
Azaleas (certain Rhododendron species) – used as shrubs in our landscapes and there are a few native azaleas as well; Elderberry (Sambucus Canadensis) – the black berries are often used to make wine; Japanese Pieris or Andomeda (Pieris japonica and other species); Rhododendron(Rhododendron maximum); St. John’s Wort (Hypericum perforatum) – Yews (Taxus baccata and T. cuspidata);
Trees (both planted and native):
Black Locust (Robinia pseudoacacia); Cherries – Wild Cherry, Black Cherry, Bitter Cherry, Choke Cherry, Pin Cherry (Prunus species); Horse Chestnut, Buckeye (Aesculus species); Laburnum or Golden Chain Tree (Laburnum anagyroides); Maple (Acer rubrum, the red maple; A. saccharum, the sugar maple; A. saccharinum, the silver maple); Oak (Quercus species);
As a last note on safety, remember that you should never try eating plants if you are even slightly doubtful about their safety. This is especially true of mushrooms. Most importantly, you should keep these plants out of reach of young children and teach older children about their dangers. If accidental ingestion occurs call your local poison center immediately! The service is free and it is better to call even if you just suspect someone may have eaten a poisonous plant.
Below are links that may be helpful for other poisonous plant questions, including further identification, plants (such as poison oak and poison ivy) that affect our skin, and notes about which plants are toxic to farm animals.
http://www.ansci.cornell.edu/plants
http://cal.vet.upenn.edu/poison/agbook/aghome.htm
http://www.alpacaweb.com/Detailed/2246.html
http://www.calacademy.org/research/library/biodiv/biblio/poison.htm