Poisonous to the touch, this plant has three leaflets that vary in size and shape, from jagged to round edges. It's often mistaken for poison oak. Growing in southern Canada, poison ivy can flourish in rocky areas, even to the point of carpeting the terrain. It can be found growing as a vine on trees and as a large or low shrub.
Poison ivy is a compound leaf plant that causes a skin rash (or severe oozing and a fever in extreme cases). Most potent in spring, it grows white, hard berries in the fall and remains poisonous all year—don’t touch the bare branches in winter.
First aid tips: If your skin is exposed to the plant’s oil, a reaction can take 12 hours to two days to develop. The oil can also stay on your clothes and furniture for days if they remain unwashed, which can result in more delayed reactions.
For relief: take an oatmeal bath, apply a cool compress to the affected skin, or take over-the-counter itch medication. If the irritation doesn’t heal or becomes severe, see a doctor.
This perennial is native to southwestern Ontario and Quebec. Pokeweed is found along meadows, edges of woods and waste areas. It has a pinkish to bright red stem that grows one to three metres high. Its leaves are dark green on top and pinkish-green on the bottom, with pink veins running through them. Pokeweed grows purplish berries and greenish-white to pink flowers blooming off short stems.
All of its parts—leaves, berries, roots, stems, and young shoots—are poisonous when ingested in large amounts. In humans, poisoning can cause a long list of unpleasant reactions, including stomach cramps, nausea, dizziness, and many more.
First aid tips: If you eat pokeweed, see a medical professional right away.
Jack-in-the-pulpit grows with a long stem, three leaflets, and a cluster of red berries. Its main leaf combs over the plant to keep pollen safe; as a result, the plant is said to resemble a preacher standing behind a pulpit. It can be found flourishing in wet soils from Manitoba to eastern Canada.
The plant contains oxalate crystals that are especially concentrated in the leaves. When eaten, the crystals cause severe pain and burning in the lips, mouth, and throat, as they pierce their way through the digestive tract. In large doses, an individual’s reaction to the poison may include breathing problems, convulsions, coma, permanent liver and kidney damage, and—in very extreme cases— death.
First aid tips: If you eat any part of a jack-in-the-pulpit plant, remove remaining bits from your mouth and rinse with cold water. Then save part of the plant for identification and call the Ontario Poison Centre.
Alder buckthorn is a shrub or small tree with purplish-black fruit. It grows along fencerows, roadsides, and lightly shaded areas from the prairie provinces to eastern Canada. Its bark and mature fruit are poisonous if eaten and can cause abdominal pain, vomiting, and diarrhea. Symptoms may worsen if more than 20 alder buckthorn berries are consumed.
First aid tips: No one likes vomiting, but it’s often a good thing to do if you’ve been poisoned by this plant: the body purges most of the nasty stuff and saves you from more severe symptoms.
If you’ve eaten alder buckthorn berries, stay hydrated and call the Ontario Poison Centre and emergency services. Keep a sample of the plant for identification.
Climbing nightshade is found climbing through and around open woods, field boundaries, fence lines, roadsides, hedges, and gardens in every province. Its clustered flowers—blue, violet, and sometimes white—surround five bright yellow stamens.
Climbing nightshade’s stems, leaves, and oblong berries are poisonous if you eat them. The mature bright red berries are less toxic than the immature green berries. Climbing nightshade suppresses the autonomic and parasympathetic nervous systems and affects digestion, so it causes all kinds of nasty symptoms.
First aid tips: You're better off safe than sorry. Keep a sample of the plant for identification and call the Ontario Poison Centre.
This medium-sized (1–3 metres) shrub has very flexible and leathery branches—they can be tied into knots while still alive—and a tough, poisonous bark. In the spring, yellow flowers bloom before leaves bud. Leatherwood is found in the woods of Ontario, Quebec, and New Brunswick. Its fruit starts off green, then changes from yellow to an orange colour by the end of summer.
Eating leatherwood bark will blister and irritate the mouth.
First aid tips: Spit out the bark and call the Ontario Poison Centre. Keep a sample of the plant for identification.
This shrub grows between 0.5–1 metre tall and is found all over Canadian woods and open slopes. It has reddish-brown branches and clustered, thin oval leaves. Thin-leaved snowberry is sometimes used as an ornamental shrub, so it’s often found indoors. Its white, round berries are poisonous and can cause vomiting, dizziness, and sedation when eaten.
First aid tips: As with alder buckthorn berries, vomiting—while an unpleasant symptom— often prevents extreme reactions by ridding the body of most of the snowberry’s toxins. Call the Ontario Poison Centre and emergency services. Keep a sample of the plant for identification.