Hundreds of cases of poisoning by plant occur every year, and these aren’t your murder-by-number type mysteries of who drugged whom. While common sense would suggest that the average adventurer would pass by a particularly lurid plant without considering the taste of its leaves, petals, or berries, the fact of the matter exists to the contrary.
One of the worst cases occurred along the Owyhee River in Oregon in 1984. A river rafter and outfitter guide mistook water hemlock roots for the edible waterparsnips, and he and five in his party ate the roots. The guide began having seizures in 45 minutes and later died, while the others required medical assistance to survive.
In the outdoors, poisonings generally result from misidentification of wild edibles, and while this was deliberate and with good intentions, many report that the plant they ate simply looked good to eat. The rule of thumb about poisonous plants: they are impossible to eradicate, and the only way to prevent poisoning is to learn which plants are poisonous and avoid them. Therefore, it is essential to educate yourself on the potential hazards of toxic plants, which means those that are toxic to ingest and contact alike.
The North American Guide to Common Poisonous Plants and Mushrooms, Nancy J. Turner and Patrick von Aderkas' extant authority on poisonous flora in North America, is hundreds of pages long, but there are several common culprits to watch out for in your wilderness wanderings.
The most common plants to avoid are the ones you most typically hear about: poison ivy, poison oak, and poison sumac. These species of toxicodendron all produce an oil called urushiol that incites a contact dermatitis that can be transferred from plants to clothes to skin and remain toxic up to five years after contact.
Toxicodendrons are not the only urushiol-producing plants, however. Few realize that the mango tree is a relative of poison ivy, and some have allergic reactions to its fruit and pollen. The mango, along with the rengas tree, lacquer tree, the shell of the cashew nut, and ginkgo biloba all produce urushiol.
Stinging nettles are also a particularly bothersome nuisance. Though found in the southeastern U.S., their hairs will stick in your skin and produce itching and a burning sensation.
Edible blue camas, a staple for indigenous North Americans, can be confused for deathcamas, and it isn’t a mistake you’ll make twice. All parts of the plant contain zygadenine, the potency of which rivals strychnine. Symptoms of ingestion include excessive salivation, nausea, vomiting, muscular weakness, ataxia, possible coma, and death.
Mushroom hunters make the potentially deadly mistake of confusing the American matsutake with toxic amanitas, such as Smith’s lepidella. Associated with Douglas fir, alder, hemlock, larch, pine, and oak, its toxin has been associated with kidney and liver failure and is prevalent in the Pacific Northwest.
Some who attempt to harvest shoots of the false lily of the valley inadvertently harvest false hellebore. The result of consuming this highly toxic plant is nausea, vomiting, cold sweats, and vertigo. Left untreated, it may eventually lead to death.
Another common misidentification in the wilderness is the confusion of water hemlock for waterparsnips; we've seen how that can turn out.
But let’s say the worst happens, and you ingest, imbibe, inhale, or otherwise introduce a toxin into your body. Here’s what you do:
Stay safe out there.