Poisonous Plants

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Poisonous Plants, Pacific Northwest

Foxglove Plant, Poisonous Plants, BC Coastal Region
Foxglove Plant, Photo By Bud Logan

It is to your benefit to learn as much about wild poisonous plants as possible, many poisonous plants can be confused with edible plants. Learn to identify poisonous plants by studying field guides, pamphlets, books, films, nature trails, botanical gardens, local markets, and local people.

Contact dermatitis from plants will usually cause the most trouble in the field. The effects may be persistent, spread by scratching, and are particularly dangerous if there is contact in or around the eyes. The principal toxin of these plants is usually an oil that gets on the skin upon contact with the plant.

Symptoms may take from a few hours to several days to appear. Signs and symptoms can include burning, reddening, itching, swelling, sun sensitivity and blisters. When you first contact the poisonous plants or the first symptoms appear, try to remove the oil by washing with soap and cold water. If water is not available, wipe your skin repeatedly with dirt or sand. After you have removed the oil, dry the area.

Ingestion poisoning can be very serious and could lead to death very quickly. Signs and symptoms of ingestion poisoning can include nausea, vomiting, diarrhea, abdominal cramps, depressed heartbeat and respiration, headaches, hallucinations, dry mouth, unconsciousness, coma, and death. Do not eat any plant unless you have positively identified it first.

Birds Foot Trefoil, Pacific Northwest
Birds Foot Trefoil, Photo By Bud Logan
Birds Foot Trefoil is a herbaceous perennial. It has a well developed tap root with side roots near the soil surface. It grows erect up to a height of 90 cm. The stems are slender, branch well, and are moderately leafy. Leaves are smooth and consist of 5 leaflets. The bloom is made up of a cluster of bright yellow flowers arranged in a group at the end of the stems. When ripe, the brown seed pods extend outward from the stalk and look like a bird’s foot. The plant remains green and succulent during and after seed ripening.

Birds Foot Trefoil is a choice food for many birds and animals. As ground cover, it provides green cover most of the year and blooms profusely.

All parts of the plant are poisonous, containing hydrogen cyanide. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death. The flowers of some forms of the plant contain traces of prussic acid and so the plants can become mildly toxic when flowering.

Butter Cup, Pacific Northwest
Buttercup, Photo By Bud Logan
Butter Cup are familiar wildflowers, they prefer to grow in open waste ground and acidic soils throughout North America, not to mention the middle of my lawn. They grow all over the Pacific Northwest.

Their irritant qualities are probably the basis of the children’s game in which one child presses a buttercup to the sensitive skin just below the chin, to see if you like butter. The slight redness caused by such casual contact is supposed, in the game, to indicate a butter lover. Prolonged contact can have more uncomfortable results. The breakdown of a glycoside releases a blister inducing juice, which can have an affect on the sensitive skin of children.

Generally buttercups have yellow cup like flowers and deeply divided leaves, which may or may not be fuzzy. The poison is located in the sap, flowers, seeds, and leaves of the plants, with the greatest concentration of the toxin occurring in vigorous growing new shoots.

Butter Cup, Pacific Northwest
Buttercup, Photo By Bud Logan
Buttercups typically cause irritation and blistering of the skin if handled, and if swallowed, an intense burning of the mouth and digestive tract, followed by nausea and convulsions. Luckily, the plant tastes so bad that victims rarely get to this state, but gardeners should be sure to wear gloves before weeding out the buttercups.


The Lupine plant grows all over the Pacific Northwest coast in great numbers. The flower is a herbaceous perennial, up to 75 cm tall. Leaves are divided into 10 to 15 narrowly oblong leaflets. The leaflets are semi smooth above, and hairy beneath. Bonnet shaped flowers are born in racemes on a single center stalk that is up to 25 cm long. The flowers bloom in early to mid summer displaying their wide range of colors from deep blue, purple, light blue, lavender, rose, pink, yellow, and white.

Lupine, Pacific Northwest
Lupine, Photo By Bud Logan

The fruit is a pod about 2.5 cm long containing several somewhat flattened seeds. The seeds are cream colored and irregularly circular, and no more than 1 cm in diameter.

They thrive in dry open fields and woodland areas, you can see them along all the highways of the coastal region of the Pacific Northwest in very thick patches. Lupine is poisonous to many animals. Poisoning varies depending on lupine species and varieties, and it is difficult to pin point to specific plant or animal since different animals become susceptible in different ways under varying range conditions.

Species and taxonomic differentiation’s between species are insufficiently characterized. Different lupines produce varying syndromes in a a given species of livestock.

Spurge Laurel Plant, Pacific Northwest
Spurge Laurel, Photo By Bud Logan
The Spurge laurel Plant is a new invasive plant for most of the south coast, it grows profusely in the Pacific Northwest. It is also found in warmer parts of the province, in roadsides, moist woods and lowland areas. It prefers shade but tolerates a wide range of conditions.

Almost all parts of the plant are highly poisonous to pets, livestock and humans. The leaves, bark and berries are toxic when touched or eaten, and can cause skin irritations, blistering, swelling of the tongue, nausea and even a coma from ingesting any part.

The Spurge laurel Plant is a slow growing, shade tolerant, long lived evergreen shrub from Europe and the Mediterranean region that has escaped from gardens and naturalized in woodlands and other shady places. Spurge laurel can grow in a wide range of conditions, but it thrives in full to partial shade and well drained soils. Its primary means of spread is by birds and rodents eating the berries although it can also spread vegetatively by root sprouts.

The plant is a threat to native species. it thrives in shady areas. Seeds in its black berries are transported to new habitat by birds and rodents. In its native climate in the Mediterranean, pests and pathogens keep the plant under control, but in British Columbia, it grows unchecked. Unlike many other invasive plant species, It does not require disturbed soil to become established.

Spurge Laurel Plant, Pacific Northwest
Spurge Laurel, Photo By Bud Logan
It creates dense strands, reducing light reaching the forest floor and limiting the growth of native plant species. As well, spurge laurel may alter soil chemistry and acidity where it germinates, preventing other plants from growing near it.

As with many invasive plants, spurge laurel likely started out as an ornamental shrub in a garden and escaped. In British Columbia, it has spread to Vancouver Island,  the Gulf Islands and the Lower Mainland,  and the south coast as far as Seymour inlet area.

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