COMMON/               SCIENTIFIC NAME

PLANT TYPE

TOXIC PART OF PLANT

DEGREE OF TOXICITY

POISONOUS COMPOUNDS

LIVESTOCK EFFECTS

Arrowgrass             (Triglochin maritima)

All

Can be severe

Glycosides (produce cyanide)

Under some conditions can cause illness and death in livestock.

Baneberry (Actaea rubra)

Forb

All, especially roots and berries

Moderate - Severe

Protoamemonin and probably a glycoside or essential oil

Stomach cramps, dizziness, vomiting, circulatory failure, headache. European species have caused death.

Bleeding-heart (Dicentra spp.)

Forb

All

Mild - Moderate

Alkaloids

Trembling, agitation, heavy salivation, vomiting, diarrhea, convulsions, difficult breathing.

Boxwood    (Buxus sempervirens)

Shrub

All

Moderate - Severe

Steroidal alkaloids (buxine)

Abdominal pains, vomiting, diarrhea. Large doses can cause convulsions, coma and death.

Bracken Fern (Pteridium aquilinum)

Fern

All

Mild - Severe

Thiaminase enzyme, carcinogens , often glycosides (prunasin)

Thiamine deficiency, which can be fatal. Cumulative effects may include cancer. Poisonous compounds can pass into milk.

Buttercups (Ranunculus spp.)

Forb

All

Mild - Moderate

Protoanemonin from ranunculin glycoside

Inflammation and blistering of skin, gastrointestinal irritation. Usually only present in fresh plants, not dried.

Camas, Death (Zigadenus venenosus)

Forb

All

Severe

Steroidal glycosidal alkaloid

Salivation, weakness, respiratory difficulty, nausea, convulsions, coma, death.

Cherry, Choke (Prunus virginiana)

Tree

Seeds, leaves, bark

Moderate - Severe

Cyanogenic glycoside (produces cyanide)

Initial rapid breathing followed by slow, difficult breathing, anxiety, excitement, confusion, headache, vomiting, dizziness, can cause death. Other related species which may be poisonous include mountain ash (Sorbus spp.), Hawthornes (Crataegus spp.), Pyracantha, Cotoneaster

Clematis (Clematis spp.)

Vine

All

Mild - Moderate

Protoanemonin from ranunculin glycoside

Inflammation and blistering of skin, gastrointestinal irritation. Usually only present in fresh plants, not dried.

Cocklebur (Xanthium strumarium)

Forb

All, esp. seeds and seedlings

Moderate - Severe

Glycosides

Loss of appetite, vomiting, weakness, ataxia, spasms, in severe cases death.

Crocus, Autumn (Colchicum autumnal)

Forb

All, especially bulb and seeds

Moderate - Severe

Alkaloids (colchiceine)

Burning pain in the mouth and throat, nausea, vomiting, diarrhea, lethargy, low blood pressure, shock, convulsions, coma, death (with larger doses).

Cucumber, Wild (Marah oreganus)

Vine

Fruit

Mild - Severe

Saponic glycosides

Chest pains, shortness of breath, can cause death.

Daffodil and Narcissus (Narcissus spp.)

Forb

All, especially bulbs

Moderate - Severe

Alkaloids (glycoside)

Dizziness, abdominal pain, nausea, vomiting, diarrhea. Large doses can cause trembling, convulsions and death.

Domestic plums, cherries, pears. peaches, apples apricots    (Prunus spp., Malus spp.,   Pyrus spp.

Seeds, leaves, bark

Mild- Moderate

Cyanogenic glycoside (produces cyanide)

Initial rapid breathing followed by slow, difficult breathing, anxiety, excitement, confusion, headache, vomiting, dizziness, can cause death in large quantities. Toxicity may be variable. Other related species which may be poisonous include mountain ash (Sorbus spp.), Hawthornes (Crataegus spp.), Pyracantha, Cotoneaster

Elderberry (Sambucus spp.)

Shrub

Leaves, stems, bark and roots

Mild - Moderate

Alkaloid and cyanogenic glycoside (produced cyanide)

Nausea, vomiting, diarrhea. Raw fruits can cause nausea.

European bittersweet (Solanum dulcamara)

Vine

All, especially green berries

Moderate - Severe

Alkaloidal glycoside (Solanine)

Abdominal pain, headache, flushed skin, tiredness. Severe cases include vomiting, thirst, difficult breathing, paralysis, dilated pupils, diarrhea, can cause death. Green potatoes contain the same chemical but in lower concentrations.

Fiddleneck or Tarweed (Amsinckia sp.)

Forb

All

Moderate

Thiaminase, Pyrrolizidine alkaloids

Appetite loss, timid, stupified, incoordination, liver lesions, enlarged liver (same as Tansy Ragwort) Foxglove
 (Digitalis purpurea) Forb All Severe Digitoxin and other glycosides Contracted pupils, nausea, vomiting, cramps, severe headache, irregular heartbeat, labored breathing, convulsions, death, usu. a problem only in hay

Golden Chain (Laburnum anagyroides)

Tree

All, esp. bark and seeds

Moderate - Severe

Alkaloid (systine) - similar effects to nicotine

Nausea, vomiting, abdominal pain, diarrhea, drowsiness, headache, dizziness, fever, irregular heartbeat, dilated pupils. Severe cases can have convulsions, coma and death. The toxicity varies widely.

Groundsel, Common  (Senecio vulgaris)

Forb

All

Moderate

Pyrrolizidine alkaloids

Liver lesions, enlarged liver, abdominal pain, weakness, staggering, death. Liver damage is permanent. Usually only eaten in hay or when wilted. Drying or storage doesn’t destroy toxins.

Hellebore, False
(Veratrum spp.)

Forb

All, esp. the rhizome

Moderate - Severe

lkaloids

Abdominal pain, vomiting diarrhea, paralysis, spasms. In severe cases can cause death. Can cause birth defects if eaten during certain gestation periods.

Hemlock, Poison (Conium maculatum)

Forb

All

Severe

Coniine and other alkaloids

Teeth grinding, muscle spasms, respiratory failure, death.

Hemlock, Water (Cicuta spp.)

Forb

All

Severe

Cicutoxin

Nausea, salivation, vomiting, convulsions, fever, low hear rate, abdominal pain, dilated pupils, delirium, coma, respiratory paralysis, death. Water Parsley (Oenanthe spp.) may contain similar toxin.

Holly, English  (Ilex aquifolium)

Shrub

Berries, leaves

Mild

Glycosides and alkaloids

Nausea, vomiting, diarrhea, drowsiness.

Horse Chestnut (Aesculus hippocastanum)

Tree

All

Moderate - Severe

Saponin glycoside, alkaloids

Inflammation of mucous membranes, vomiting, thirst, weakness, muscular twitching, dilated pupils, stupor, paralysis. Coma and death can occur in severe cases.

Horsetail (Eqisetum arvense)

Fern-ally

All

Mild - Moderate

Thiaminase

Destroys vitamin B1 - Symptoms include weight loss, weakness, eventual death.

Yellow Flag Iris
(Iris pseudacorus)

Forb

All, esp. rhizomes

Moderate - Severe

Glycoside

Abdominal pain, nausea, vomiting, diarrhea, fever, large doses can cause death.

Ivy, English
(Hedera helix)

Vine

All, esp. leaves and berries

Moderate

Triterpene saponins (glycosides)

Large quantities cause vomiting, diarrhea, spasms, staggering, paralysis.

Knapweed, Russian and Yellowstar Thistle
(Centaurea spp.)

Forb

All

Moderate

Brain deterioration resulting in “Chewing disease”, can eventually cause death by starvation.

Knotweeds
(Polygonum spp.)

Forb

All

Mild

Oxalic acid

Large quantities can cause interference with calcium metabolism in the body and possible phototoxicity.

Lambsquarters
(Chenopodium album)

Forb

All

Mild

Oxalates

Large quantities can cause interference with calcium metabolism in the body and possible phototoxicity.

Larkspur
(Delphinium spp.)

Forb

All

Severe

Alkaloids (delphinine)

Constipation, bloat, dilation of pupils, vomiting, depression, paralysis, death.

Laurel, English (Prunus laurocerasus)

Shrub

Seeds, leaves, bark

Mild - Moderate

Cyanogenic glycoside (produces cyanide)

Initial rapid breathing followed by slow, difficult breathing, anxiety, excitement, confusion, headache, vomiting, dizziness, can cause death in large quantities. Toxicity may be variable. Other related species which may be poisonous include mountain ash (Sorbus spp.), Hawthornes (Crataegus spp.), Pyracantha, Cotoneaster.

Lily of the Valley (Convallaria majalis)

Forb

All

Severe

Cardiac glycosides (digitalis-like)

Burning pain in mouth and throat, salivation, nausea, vomiting, abdominal pain, headache, dilated pupils, slow and irregular heartbeat, sometimes coma and death.

Locust,           Black or Honey (Robinia pseudo-acacia)

Tree

All

Mild - Moderate

Poisonous proteins

Lassitude, nausea, vomiting, abdominal pain, diarrhea, delirium, coma, death in livestock in severe cases.

Lupine      (Lupinus spp.)

Forb

All

Moderate

Alkaloids (lupinine)

Birth defects, spasms, vomiting, nausea, dizziness, headache, abdominal pain, and in severe cases death.

Nightshade, Black (Solanum nigrum)
 

Nightshade, Hairy (Solanum sarrachoides)

Vine

All, especially green berries

Moderate - Severe

Alkaloidal glycoside (Solanine)

Abdominal pain, headache, flushed skin, tiredness. Severe cases include vomiting, thirst, difficult breathing, paralysis, dilated pupils, diarrhea, can cause death. Green potatoes contain the same chemical but in lower concentrations.

Oak           (Quercus spp.)

Tree

All, but esp. acorns

Slight

Tannins (?)

Constipation, blood in urine.

Pea, Wild (Lathyrus spp.)

Forb

Foliage, seeds

Mild

Toxic amino acids

Paralysis, convulsions, death. Toxic only in large quantities.

Pigweed (Amaranthus spp.)

Forb

All

Mild

Oxalates, nitrates

Large doses can cause fluid accumulation around kidneys.

Poison Oak Poison Ivy (Toxicodendron spp.)

Shrub/ Vine

All

Mild - Moderate

Oleoresin (urushiol)

Itching, burning, redness of skin, blisters

Ponderosa Pine (Pinus ponderosa)

Tree

Needles

Mild - Moderate

Abortion

Ragwort, Tansy (Senecio jacobea)

Forb

All

Moderate

Pyrrolizidine alkaloids

Liver lesions, enlarged liver, digestive disturbances, restlessness, lack of coordination, weakness, staggering, death. Liver damage is permanent. Usually only eaten in hay or when wilted. Drying or storage doesn’t destroy toxins. Toxins can contaminate milk and honey.

Rhododendron (Rhododendron spp.)

Shrub

All

Mild - Severe

Glycosides

Burning of lips, mouth, salivation, nausea, severe vomiting, coma and death in the most severe cases. The toxin can contaminate honey.

Rhubarb   (Rheum rhabarbarum)

Forb

Leaves

Moderate

Oxalic acid and oxalates (irritant poison)

Abdominal pain, nausea, vomiting, difficulty breathing, drowsiness, large doses can cause convulsions, coma and death. Oxalic acid interferes with calcium metabolism as well.

Scotch Broom (Cytisus scoparius)

Shrub

All

Mild - Moderate

Quinolizidine alkaloids

Nausea, vomiting, dizziness, headache, abdominal pain.

Serviceberry (Amalanchier alnifolia)

Shrub

Leaves, twigs

Mild - Moderate

Cyanogenic glycoside (produces cyanide)

Initial rapid breathing followed by slow, difficult breathing, anxiety, excitement, confusion, headache, vomiting, dizziness.

Skunk Cabbage (Lysichitum americanum)

Forb

All

Mild - Moderate

Calcium oxalate crystals

Physical irritation and swelling of mouth, throat, etc. as crystals pierce the skin.

Snowberry (Symphoricarpos albus)

Shrub

Berries

Moderate - Severe

Alkaloids

Severe Vomiting, dizziness, semi-comatose state.

Sorrel                 (Rumex spp.)

Forb

All

Mild

Oxalic acid

Large quantities can cause interference with calcium metabolism in the body.

St. John’s-Wort (Hypericum perforatum)

Forb

All

Mild - Moderate

Hypericin

Photosensitization - blisters, swelling and lesions on the skin, particularly light-skinned animals. Subsequent exposure has more severe symptoms. Loss of appetite, diarrhea, increased respiration and heartbeat, high temp., blindness, convulsions, sometimes coma and death. Symptoms are often delayed.

Swamp laurel (Kalmia sp.)

Shrub

Leaves, flowers

Mild - Moderate

Andromedo-toxin, arbutin

Burning of lips, mouth, salivation, nausea, severe vomiting, coma and death in the most severe cases.

Tansy, Common (Tanacetum vulgare)

Forb

All

Moderate - Severe

Tanacetin

Rapid pulse, stomach inflammation, convulsions, abortion, occasionally fatal. However, rarely grazed because of strong taste and smell.

Tarweed (Amsinckia spp.)

Forb

All

Moderate

Pyrrolizidine alkaloids

Liver lesions, enlarged liver, digestive disturbances, restlessness, lack of coordination, weakness, staggering, death. Liver damage is permanent. Usually only eaten in hay or when wilted. Drying or storage doesn’t destroy toxins.

Vetch, Common (Vicia sativa)

Forb

Foliage, seeds

Mild - Severe

Cyanogenic glycosides (produces cyanide)

Amount of toxins in plants highly variable. Initial rapid breathing followed by slow, difficult breathing, anxiety, excitement, confusion, headache, vomiting, dizziness, can cause death.

Yarrow      (Achillea millefolium)

Forb

All

Mild

Glucosides and alkaloid

If eaten in quantity can cause gastric problems.

Yew                     (Taxus brevifolia)

Tree

All, except perhaps the flesh around the seed.

Moderate - Severe

Alkaloid (taxine), ephedrine, cyanogenic glycoside

Gastroenteritis, nausea, vomiting, diarrheas, rash, drowsiness, irregular heartbeat, labored breathing, trembling, collapse. Large amounts can cause death.