Most plants are totally helpless. They can’t run away or defend themselves when we chop them, burn them, or eat them alive. There are a few plants, however, that are more than capable of defending themselves and putting the hurt on humans. Some of these plants look like food (but aren’t), and some aren’t remarkable looking at all (but can cause harm). In either case, you should get to know these trouble makers and avoid them all.
Plants You Should Never Touch
Some plants are armored with obvious defenses. Cacti can be covered with needles, ready to puncture anyone who carelessly bumps into them. Stinging nettle is another well-armed plant, with leaves and stems that deliver a painful sting as soon as they touch bare skin. Not all plants have such obvious protections, and some defend themselves with delayed damage.
Poison Ivy Poison oak, ivy, and sumac all contain oils that produce a rash when they come into contact with the skin of someone who is allergic (90% of us are allergic). Of these three trouble makers, poison ivy (Toxicodendron radicans) is the most commonly found and the sneakiest. The very same species can appear as a small plant, a free-standing shrub, or a large climbing vine-covered in fuzzy hairs. All plant parts, from roots to berries, contain a clear oily phenol called urushiol. This compound causes the allergic rash, in roughly two million people in the U.S. each year. For your best chance of staying out of this plants reach, remember the old saying “leaves of three, let them be.” Learn to identify it in its many forms, and don’t touch or burn any part of it.
Giant Hogweed A fairly recent introduction to eastern North America, giant hogweed (Heracleum mantegazzianum) is a European native that is actually branded as a “noxious weed” by the feds. This mighty member of the carrot family may cause foragers to think that they’ve discovered a huge wild carrot since it’s covered in hairs (like a wild carrot should be). But don’t go pulling it up by the stem just yet. Exceeding heights of 12 feet, this tall plant has hairy stalks, carrot-like leaves, and white umble flower clusters. But it’s not even safe to touch, let alone eat. This entire plant is covered and filled with a dangerous compound that causes a severe light-sensitive skin reaction. Within 48 hours of contact, the plant causes dark, painful blisters that form after exposure to sunlight. These blisters are deep, painful, and can leave hideous scarring. And don’t get any of this compound in your eyes, or else blindness can result.
Plants You Should Never Eat
These berries, roots, leaves, and shoots are occasionally confused with wild food plants, but they’re definitely on the “do not eat” list.
Sometimes confused with poison ivy, Virginia creeper (Parthenocissus quinquefolia) can be found growing throughout the central and eastern United States. A quick leaf count will help you determine the difference since creeper has palmate compound leaves with five heavily toothed leaflets, and poison ivy has only three leaflets with just a few teeth (or none). There’s another reason that a few people get confused since a small percentage of people can get a rash from creeper (similar to poison ivy blisters). The real harm comes from the small purplish-black fruits, which are poisonous and have caused kidney damage and fatalities in humans. Look for Virginia creeper between Manitoba and Florida and as far west as Texas. Then don’t eat it.
The white hellebore (Veratrum album) is dangerous because of its ability to drop blood pressure and affect the heart, and because it can resemble ramps (a wild garlic, aka Allium ursinum) when hellebore is young. Mature plants can grow to heights of 6-7 feet, and it favors wet meadows and mountainous areas, particularly New England and Alaska. All parts are toxic, especially the seeds which contain veratridine and cevadine. Poisoning symptoms can include vomiting and severe GI upset, paralysis, a dangerous drop in blood pressure (hypotension and bradycardia), vision problems, and maybe even death.
Much larger than its cousin the poison hemlock, water hemlock (Cicuta maculata) is a large perennial plant that can exceed eight feet in height when growing in fertile wetland areas. Like other umble family members, water hemlock has large clusters of white flowers. It also has the strongest poison in North America. It has been called suicide root by the Iroquois people and “cowbane” because ingestion can kill a full-grown cow in as little as 15 minutes. Symptoms after human consumption include projectile vomiting, loss of consciousness, pain, convulsions, and death. Consuming even a small amount of this plant can kill or cause permanent nervous system damage.
In late summer, the colorful pink stems and shiny dark purple fruits of the pokeweed plant (Phytolacca americana) can be very attractive, especially to children. And while these juicy berries are consumed by many birds and some mammals, they can be deadly to humans. Just a few berries have killed infants, and a handful can kill an older child. A slightly larger amount can kill an adult. There’s a unique toxin in pokeweed (phytolaccatoxin), and it is present throughout the plant. This toxic can cause severe gastrointestinal distress and kill a person by causing respiratory paralysis. I know these grape-like clusters of pretty purple-black berries look like food, and people do eat the shoots of pokeweed in the spring (after boiling in three changes of water), the plant is best avoided, from root to crown.
It sounds like food, with synonyms like “Indian apple root,” but mayapple (Podophyllum peltatum) is also called the “American mandrake,” and it’s alarmingly toxic to mammals. This small plant often grows in clumps or thick patches in woodland areas through the eastern U.S. Each plant has two large leaves with one white flower in the fork between the leaves. Once pollinated, the flower becomes a small lemon-shaped fruit in mid-summer. While the flesh of the ripe fruit is edible to humans (safest if cooked, the seed must be removed), unripe fruit, and all other parts are strongly poisonous due to a compound called podophyllin. Consumption of any part (other than the flesh of ripe fruit) can cause vomiting, diarrhea, coma, and death.
There are at least 250 species of rhododendrons (and related shrubs in the Heath family) throughout North America, with lots of different names. One of the Native American names hints at a gloomy usage, as the name translates into English as “suicide bush.” All parts of the plant (even the nectar removed by honeybees) contain grayanotoxins. These compounds can cause nausea, vomiting, drooling, or more severe symptoms like cardiac issues, coma, and death. Even the honey made from the plant is toxic. This shrub is often found in acidic soils and growing as an understory shrub. The shiny green leaves look a lot like bay leaves, but these should never end up in your survival stew. Because of their terrible taste, it’s unlikely that anyone would accidentally consume enough of the plant to cause serious harm, but it’s best to avoid it anyway.
What To Do If Poisoned
Most wild plant parts are “in-edible” to humans, meaning that they neither offer nutrition nor harm, but then there are the plants and plant parts that can hurt us. If you suspect that you or someone in your group has ingested a poisonous plant – you need to act immediately. Most plant poisonings are treatable and cause only mild distress, but you don’t want to wait around to see if things get worse. A speedy response to poisoning will limit damage to the body and potentially save someone’s life.
On “The Grid” Do what you’ve been told to do your whole life, call 911 immediately if you are facing any medical emergency (even a poisoning). They need to know where you are (give them the address and local cross streets or crossroads). They need to know what happened, to whom, and any other details you can muster. Provide the name or suspected name of the plant and all symptoms that the victim is experiencing. EMS should also know how much was consumed when it was eaten and the general features of the victim (like age, weight, and preexisting medical conditions). Then wait for the ambulance to arrive. You don’t need to get behind the wheel right before you projectile vomit or lose consciousness. Now EMS has to deal with a poisoning victim that’s also been in a car wreck.
When Help Is Delayed/ “Off The Grid” When definitive medical care is not readily available, you’ll have to make all the hard decisions yourself. It’s generally best to get the plant out of their stomach if it was eaten within the last hour. Chug several glasses of water and induce vomiting by fingering the back of the throat (if you don’t have ipecac syrup in your med kit). Repeat this several times until the stomach is clear. Keep tabs on the victim’s vital signs – monitoring for shock, paralysis, or respiratory distress. Be prepared to give CPR and attempt to reach (or bring in) medical care ASAP.