Database of Toxic Plants in the United States

Below you will find the comprehensive list of toxic plants that has been compiled from many other sources. They have been presorted in three ways: 1) alphabetically by common name, 2) alphabetically by scientific name, and 3) by growth type (browse, forb, grass, shrub, tree) and then alphabetically within each type by common name.

For the third option: browse means woody species generally smaller than shrubs; forbs are leafy species that may be either monocot or dicot, and may be annual, perennial, or biennial.

Last on the page you will find a listing of some common symptoms by toxin: these are notated in the database by 'See list for _____'. The symptoms were simply too numerous to list within the database. Bear in mind that your horse may or may not display all of the symptoms for any one toxin, depending upon the severity of the toxicity.

ALPHABETICALLY BY COMMON NAME

Common Name	Scientific Name	Area Affected	Toxin (If Known)	Type	Comments; Regional Names
Acacia	Acacia & Robinia spp.	Gastric & Nervous Systems	Glycosides; Phytotoxin	Tree	False acacia; black locust
Aconite	Aconitum columbianum	Gastric; Colic	Alkaloid Aconitine	Forb	Monkshood; not toxic when dried; used in homeopathy
Akee	Blighia sapida	Teratogenic; Fetal	Teratogens	Tree
Alsike clover	Trifolium hybridum	Liver Disease; Hepatitis; Teratogenic	Mycotoxin	Forb	When wet/humid
American coffee berry	Gymnocladius dioica	Gastric; Diarrhea; Death	Alkaloid Cytisine	Tree	Kentucky mahogany/coffee tree; nicker tree; stump tree
Anemone	Ranunculus spp	Colic/Diarrhea	Glycosides; Protoanemonin	Forb	See buttercups; not toxic when dried
Arborvitae	Thuja occidentalis	Fetal Damage	Thujone	Tree	Not common: toxic if consumed in quantity
Arrowgrass	Triglochin maritimum	Nervous; Respiratory; Death	Cyanide; Prussic Acid	Grass	Also toxic when dried in hay.
Autumn crocus	Colchicum autumnale	Teratogenic; Fetal; Neurologic	Teratogens	Browse	Meadow saffron
Avocado	Persea americana	Colic/Diarrhea; Mastitis; Cardiac; Death	Persin	Tree	Guatemalan variety only; fruit/seeds/leaves
Azalea	Rhododendron spp.	Colic/Diarrhea; Tremors	Cyanide; Ursol Acid	Shrub	Also toxic when dried; rhododendrons
Bastard toadflax	Comandra pallida		Se Accumulator	Forb
Beardtongue	Penstemon calycosus	See List For Selenium Toxicosis	Se Accumulator	Forb
Bermuda grass	Cynodon dactylon	Gastric System	May have ergot	Grass
Be-still	Thevetia thevetioides	Colic/Diarrhea; Sudden Death	Glycosides	Tree	Lucky nut tree; yellow oleander
Birdsville indigo	Indigofera linnaei	Photosensitization; Hepatotoxic	Indospicine	Forb
Bishop's weed	Ammi majus	Photodermatitis	Coumarin	Forb	Large bullwort
Bitter nightshade	Solanum dulcamara	Colic/Diarrhea	Alkaloids; Solanine	Forb	European bittersweet; climbing nightshade
Bitter sneezeweed	Helenium hoopesii	GI Irritant	Sesquiterpene Lactone	Forb	Sneezeweed
Bitterweed	Hymenoxys odorata	Mouth/GI Irritant	Hymenoxen	Forb
Black henbane	Hyoscyamus niger	Convulsions; Coma; Death	Glycoalkaloids	Forb
Black locust	Robinia pseudoacacia	Ataxia; Colic/Diarrhea; Paralysis	Lectin	Tree	Bark is most toxic
Black nightshade	Solanum nigrum	Colic/Diarrhea	Alkaloids; solanine	Forb	Deadly nightshade
Black walnut	Juglans nigra	Weakness; Laminitis; Dermatitis	Unknown	Tree
Bladderpod	Lesquerella gordonii	Diarrhea; Weakness; Death	Saponins	Shrub
Bleeding heart	Dicentra spectabilis; formosa	Convulsions; weakness; staggering	Alkaloids; Isoquinoline	Forb	Dutchman's breeches
Bloodroot	Sanguinaria canadensis	Gastric; Muscular; Respiratory	Alkaloids	Forb
Blue mustard	Chorispora tenella	Deformed Foals	Glucosinolates	Forb
Bouncing Bet	Saponaria officinalis	Gastric/Diarrhea; Depression	Saponin	Forb	Soapwort
Boxwood	Buxus spp.	Neurologic; Colic; Respiratory	Cyclobuxin (Alkaloid)	Shrub	All plant parts toxic
Bracken fern	Pteridium aquilinum	Thiamin Deficiency; Ataxia	Thiaminase; Filicin	Browse	Western brackenfern; all parts poisonous
Bristlegrass	Setaria spp	Physical; Mouth/GI; Foam/Drool	Physical	Grass	Green bristlegrass; hooked bristlegrass
Broom groundsel	Senecio spartioides	Hepatotoxic; Weakness	Alkaloids	Forb
Broom snakeweed	Gutierrezia sarothrae	Se List; Abort/Repro	Se Accumulator; Terpenes	Shrub	Turpentine weed; snakeweed; matchweed
Broomweed	Gutierrezia microcephala	Abortion; See List For Se Toxicosis	Se Accumulator	Forb
Buckeye	Aesculus hippocastanum	Neurologic; Weakness; Trembling	Saponin	Tree	All parts toxic; horse chestnut
Buckwheat	Fagopyrum esculentum	Photosensitization	Fagopyrin	Forb
Budsage	Artemesia spinescens	Neurological	Possibly monoterpenes	Shrub
Buffalo burr nightshade	Solanum rostratum	Colic/Diarrhea	Alkaloids; Solanine	Forb	Buffalobur
Buffalobur	Solanum rostratum	Colic/Diarrhea	Alkaloids; Solanine	Forb	Buffalo burr nightshade
Bull nettle	Solanum carolinense	Colic/Diarrhea	Alkaloids; Solanine	Forb
Bull thistle	Cirsium vulgare	See List For Nitrate Toxicosis	Nitrates	Forb
Burdock	Arctium minus	Mouth/GI	Physical	Forb
Burr trefoil	Medicago polymorpha	Photosensitization From Liver Failure	Mimosine	Forb
Burrow weed	Haplopappus tenuisecta	Neurological; Ataxia; Muscular	Tremetol	Forb	Trembles
Butter and eggs	Linarea vulgaris	Gastric System	Glycosides	Forb	Yellow toadflax
Buttercup	Ranunculus spp	Mouth/GI Irritant/Colic	Protoanemonin (Alkaloid)	Forb	All buttercups; loss of milk production
Butterweed	Senecio glabellus	Hepatotoxic	Alkaloids	Forb
Button bush	Cephalanthus occidentalis	Gastrointestinal	Glycosides	Shrub
California buckeye	Aesculus californica	GI Irritant	Saponin; Aesculen	Tree	New growth; leaves; nuts
Canada thistle	Cirsium arvense	See List For Nitrate Toxicosis	Nitrates	Forb
Carolina jessamine	Gelsemium sempervirens	Gastric; Weakness; Respiratory	Alkaloids	Shrub	Evening trumpetflower, false jessamine
Castor bean	Ricinus communis	Colic/Diarrhea; Ataxia	Ricin (Toxalbumin); Lectin	Forb	Seeds in particular; highly toxic; see rosary pea
Cat's ears	Hypochaeris radicata	Possible stringhalt; Neurological	Alkaloids	Forb	Flatweed, false dandelion
Cheatgrass	Bromus tectorum	Mouth/Digestive Tract	Physical	Grass	Downy brome
Chinaberry	Melia azedarach	Gastric; Cardiac; Diarrhea	Terpenes; unidentified	Tree
Chokecherry	Prunus virginiana	Sudden Death	Cyanide/Glycosides	Tree	Drought & freeze increase toxicity
Christplant	Euphorbia milii	Skin Irritations; Mouth/GI	Latex	Shrub	Crown of thorns
Clematis	Clematis spp.	Colic/Diarrhea; Neurotoxic	Protoanemonin (Alkaloid)	Browse	All plant parts
Climbing bittersweet	Celastrus scandens	Neurological; Gastric	Solanine	Browse	Nightshades
Climbing nightshade	Solanum dulcamara	Colic/Diarrhea	Alkaloids; Solanine	Forb	European bittersweet; bitter nightshade
Clovers	Trifolium spp	Photosensitization; Hepatotoxic	Slaframine	Forb
Cockle burrs	Xanthium spp.	Mouth/GI tract	Physical	Forb	Cockleburs; 2 spp; seedlings/seeds toxic
Cockleburs	Xanthium spp.	Mouth/GI tract	Physical	Forb	Cockle burrs; 2 spp; seedlings/seeds toxic
Cockspur	Crataegus crus-galli	Colic/Diarrhea	Physical impaction	Tree	Hawthorn; cockspur hawthorn; fruits toxic
Coffee weed	Cassia occidentalis	Lameness; Muscle Weakness	Anthraquinone	Forb	Sienna weed
Cohosh	Actaea rubra	Respiratory; Cardiac	Glycoside	Forb	Red baneberry
Colorado rubberweed	Hymenoxys richardsonii	GI Irritant; Photosensitization	Sesquiterpene	Forb	Rubberweed; pingue
Comfrey	Symphytum officinale	Chronic Poisoning; Liver	PA/Alkaloids	Forb
Common groundsel	Senecio vulgaris	See List For PA	PA/Alkaloids	Forb
Common vetch	Vicia sativa	Blindness; Convulsions	Cyanide; Neurotoxin	Forb
Copperweed	Oxytenia acerosa	GI Irritant; Weakness; Coma	Possibly sesquiterpenes	Shrub
Corn cockle	Agrostemma githago	Muscles; ataxia	Saponin	Forb	Seeds in particular
Corn lily	Veratrum californicum	Colic/Diarrhea; Teratogenic	Steroid (Alkaloids)	Forb	Western false hellebore; false hellebore; chasing green
Creeping charlie	Glechoma hederacea	Respiratory; Sweating	Glechomin	Forb	Ground ivy; all parts when fresh; not in stored hay
Creeping/trailing indigo	Indigofera spicata	Teratogenic; Ataxia; Hepatotoxic	Indospicine	Forb	Picas
Crofton weed	Ageratina adenophora	Ataxia; Muscular	Tremetol	Forb	Eupatorium adenophorum
Crown of thorns	Euphorbia milii	Skin Irritations; Mouth/GI	Latex	Shrub	Christplant
Crown vetch	Coronella varia	Weight loss; Abnormal behavior	Neurotoxin	Forb
Curly dock	Rumex crispus	Kidney; Tremors; Coma; Death	Oxalates	Forb
Curlycup gumweed	Grindelia squarrosa	See List For Selenium Toxicosis	Se Accumulator	Forb	Resinweed; gumweed
Cutleaf nightshade	Solanum	Colic/Diarrhea	Alkaloids/Glycosides	Forb
Daffodil	Narcissus spp.	Gastric/mouth, Dermatitis	Alkaloids; Narcissine	Forb	Bulbs in particular; narcissus
Deadly nightshade	Solanum nigrum	Colic/Diarrhea; Collapse	Alkaloids/Solanine	Forb	Black nightshade; drought increases toxicity
Deathcamas	Zigadenus spp	Neurotoxin; Colic; Death	Alkaloids	Forb	15 spp deadly within days; 8-10 lbs
Delphinium	Delphinium spp	Paralysis; Respiratory	Aconitin (Alkaloid); Nitrates	Forb	Larkspur
Dogbane	Apocynum cannabinum	Cardiac; Sudden Death	Cardiac Glycosides	Forb	Hemp dogbane; Indian hemp; under 24 hours
Downy brome	Bromus tectorum	Mouth/Digestive Tract	Physical	Grass	Cheatgrass
Dutchman's breeches	Dicentra cucullaria	Trembling; Diarrhea; Convulsions	Alkaloids	Forb	Squirrel corn; bleeding heart family
Easter lily	Lilium longiflorum	Kidney; Gastric; Weakness	Unidentified	Forb
Elderberry	Sambucus canadensis	Cardiac/Sudden Death; Ataxia	Nitrates; Glycosides	Tree	See list for nitrate toxicosis; death within minutes
English ivy	Hedera helix	Gastric; Respiratory; Coma; Death	Saponin	Browse	Entire plant
European bittersweet	Solanum dulcamara	Colic/Diarrhea	Alkaloids	Forb	Bitter nightshade; climbing nightshade
European hemlock	Conium maculatum	Death; Teratogenic	Teratogens; Alkaloids	Forb	Spotted/poison hemlocks; 2-3 hours
European milkvetch	Astragalus spp	Fetal Damage	Teratogens	Forb
Evening trumpetflower	Gelsemium sempervirens	Gastric; Weakness; Respiratory	Alkaloids	Shrub	Carolina jessamine, false jessamine
False dandelion	Hypochaeris radicata	Lameness	Alkaloids	Forb	Cat's ears, flatweed
False hellebore	Veratrum californicum	Colic/Diarrhea; Teratogenic	Steroid (Alkaloids)	Forb	Western false hellebore; corn lily; chasing green
Fetterbush	Pieris spp.	Colic/Diarrhea	Arbutin	Shrub
Fiddleneck	Amsinckia menziesii	Hepatotoxic; Weight Loss	PA; Nitrates	Forb	Tarweed; see list for nitrate toxicosis
Field bindweed	Convolvulus arvensis	Colic/Diarrhea; Cardiac	Alkaloids; Nitrates	Forb	Morning glory; see list for nitrate toxicosis
Field mustard	Brassica rapa	Gastric/Diarrhea; Anorexia	Glucosinolates	Forb
Fireweed	Kochia scoparia	Photosensitization; Hepatotoxic; Nitrate	Oxalates; Nitrates	Forb	Kochia; summer cypress
Flatweed	Hypochaeris radicata	Lameness	Alkaloids	Forb	Cat's ears, false dandelion
Flixweed	Descurainia sophia	Deformed Foals	Teratogens	Forb	Sophia, tansy mustard
Foxglove	Digitalis purpurea	Cardiac; Gastric; Sudden Death	Glycosides; saponins	Forb	Purple Foxglove; under 24 hours
Foxtail barley	Hordeum jubatum	Mouth/GI	Physical	Grass
Freckled milkvetch	Astragalus lentiginosus	Neurological	Neurotoxin	Forb
Fringed sage	Artemisia frigida	Neurological	Neurotoxin	Shrub	Prairie sagewort
Fumewort	Corydalis spp.	Convulsions; Staggers; Collapse	Alkaloids	Forb	Several species are included.
Gambel's oak	Quercus gambelii	Colic/Diarrhea	Tannic Acid; Gallotannins	Tree	Tannins in young leaves; bark; acorns
German millet	Setaria italica	Kidney; Joint; Bone		Grass	Crop/pasture grass
Golden chain tree	Laburnum anagryroides	GI; Neuromuscular	Alkaloids; Cytisine	Tree	Entire plant; seeds in particular
Golden oatgrass	Trisetum flavescens	Weakness; Weight loss; Calcinosis	Unknown	Grass
Golden weed	Haplopappus engelmannii	See List For Selenium Toxicosis	Selenium	Shrub
Goldenrods	Solidago spp	See List For Nitrate Toxicosis	Nitrates	Forb
Goose grass	Triglochin spp.	Ataxia; Death	Cyanogenic Glycosides	Grass	Arrow/pod grasses; within minutes
Goosegrass	Eleusine indica	Gastric Distress	Alkaloids	Grass	Wiregrass
Greasewood	Sarcobatus vermiculatus	Ca Deficiency; Colic/Diarrhea	Oxalates	Shrub
Green bristlegrass	Setaria spp	Mouth/Throat/Gastric	Physical	Grass	Bristlegrass; hooked bristlegrass
Green false hellebore	Veratrum eschscholtzii	Fetal Damage; Colic/Diarrhea	Protoanemonin; Alkaloids	Forb	Cyclops foals
Ground ivy	Glechoma hederacea	Respiratory; Sweating	Glechomin	Forb	Creeping charlie; all parts when fresh; not in stored hay
Groundsel	Senecio plattensis	Hepatotoxic; Teratogenic; Weakness	PA; Teratogens	Forb	Ragwort.
Gumweed	Grindelia squarrosa	See List For Selenium Toxicosis	Se Accumulator	Shrub	Curlycup gumweed; resinweed
Hairy nightshade	Solanum sarrachoides	Colic/Diarrhea	Alkaloids	Forb
Halogeton	Halogeton glomeratus	Kidney; Colic/Diarrhea	Oxalates	Forb
Hard maple	Acer spp.	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Hawthorn	Crataegus crusgalli	Colic/Diarrhea; Impaction	Physical	Tree	Cockspur; fruits
Heliotrope	Heliotropium arborescens	Weight Loss; hepatotoxic	Pyrrolizidin	Forb	Seeds in particular
Hemp	Cannabis sativa	Neurotoxin	60 Compounds	Forb	Marijuana
Hemp dogbane	Apocynum cannabinum	Cardiac; Sudden Death	Cardiac/Cyanogenic Glycosides	Forb	Dogbane; Indian hemp; all parts toxic
Hoary alyssum	Berteroa incana	GI; Founder; Laminitis; Edema	Unknown	Forb
Honeysuckle	Ionicera periclymenum	Diarrhea; Lethargy		Shrub	Plants and berries
Honey mesquite	Prosopis glandulosa	Colic/Diarrhea; Impaction	Physical	Tree	Fruits only; mesquite
Hooked bristlegrass	Setaria spp	Mouth/Throat/Gastric	Physical	Grass	Green bristlegrass; bristlegrass
Horse chestnut	Aesculus hippocastanum	Muscles; Ataxia	Saponin; Aesculen	Tree	All parts toxic; buckeye
Horse nettle	Solanum carolinense	Colic/Diarrhea; Paralysis; Death	Alkaloids	Forb	Nightshades
Horsetails	Equisetum spp.	Weakness; Stumbling; Arrhythmia	Aconitic Acid	Forb	Snakegrass; scouring rush; all parts toxic; B1 may help
Houndstongue	Cynoglossum officinale	Liver; Weight Loss	Hepatotoxin/PA	Forb	All stages of plant; liver failure
Hyacinth	Hyacinthus orientalis	Diarrhea; Colic	Alkaloids	Forb	Garden hyacinth; foliage may cause dermatitis
Hydrangea	Hydrangea spp.	Gastric/Diarrhea; Respiratory	Cyanogenic Glycosides	Shrub	Several spp; entire plant toxic
Indian hemp	Apocynum cannabinum	Cardiac; Sudden Death; Colic	Cardiac Glycosides	Forb	Dogbane; hemp dogbane; under 24 hours
Indian paintbrush	Castilleja linariaefolia	See List For Selenium Toxicosis	Se Accumulator	Forb
Ironweed	Sideranthus grindelioides	See List For Selenium Toxicosis	Se Accumulator	Shrub
Jack-in-the-Pulpit	Arisaema triphyllum	Lips/Mouth/Tongue; Salivation	Oxalates	Forb	Several spp.
Jamestown weed	Datura stramonium	Cardiac; Coma; Death	Hyoscyamine (Alkaloid)	Forb	Stinkweed; mad apple; jimson weed; thornapple
Japanese yew	Taxus cuspidata	Cardiac; Sudden Death	Taxine (Alkaloid)	Shrub	All parts except berries; death within hours
Jerusalem cherry	Solanum pseudocapsicum	Colic/Diarrhea; See Nitrate List	Alkaloids; Nitrates	Shrub
Jessamine, day blooming	Cestrum diurnum	Calcinosis; Lameness/Weakness	Hyoscine	Tree	Wild jasmine
Jessamine, false	Gelsemium sempervirens	Gastric; Weakness; Respiratory	Alkaloids	Shrub
Jessamine, night blooming	Cestrum nocturnum	Lameness/Muscle Weakness	Atropine-like Alkaloids	Tree
Jimmy weed	Haplopappus heterophyllus	Neurological; Muscle; Ataxia	Tremetol	Shrub	Southern goldenbush; trembles
Jimson weed	Datura stramonium	Teratogenic; Neurological; See Nitrates	Alkaloids; Nitrates	Forb	Stinkweed; mad apple; jamestown weed; thornapple
Johnsongrass	Sorghum halepense	Ataxia; Cardiac	Cyanogenic Glycosides	Grass	Within minutes
Kentucky coffee tree	Gymnocladius dioica	Gastric/Diarrhea, Respiratory	Cytosine	Tree	Kentucky mahogany, nicker, stump, American coffee tree
Kentucky mahogany tree	Gymnocladius dioica	Gastric/Diarrhea, Respiratory	Cytosine	Tree	Kentucky/American coffee tree; nicker tree; stump tree
Klamath weed	Hypericum perforatum	Skin; Photosensitize	Naphthodianthron; Hypericin	Forb	St. Johnswort; goatweed?
Kleingrass	Panicum coloratum	Liver Disease; Hepatitis	Mycotoxin	Grass	Wet/humid conditions; not in hay; dew poisoning
Kochia	Kochia scoparia	Photosensitization; Hepatotoxic; Nitrate	Oxalates; Nitrates	Forb	Fireweed, summer cypress
Lamb's tongue groundsel	Senecio integerrimus	Hepatotoxic	PA	Forb
Lambsquarters	Chenopodium album	See List For Nitrate Toxicosis	Nitrates	Forb
Lantana	Lantana camara	Liver damage; depression; neurological	Lantadene	Shrub	Several spp.; entire plant
Large bullwort	Ammi majus	Photodermatitis	Coumarin	Forb	Bishop's weed
Larkspur	Delphinium spp	Colic; Respiratory Paralysis; Death	Aconitin; Esters; Nitrates	Forb	Delphinium; poison weed; 80 spp?; young plants especially
Laurel	Kalmia spp.	Colic/Diarrhea; Depression; Ataxia	Alkaloids; Arbutin	Shrub	Several spp.; leaves especially toxic
Leafy spurge	Euphorbia esula	Photosensitivity; Colic/Diarrhea	Latex	Forb	Especially light-colored horses
Lily of the valley	Convallaria majalis	Sudden Death; Cardiac; Gastric	Glycosides	Forb	Under 24 hours
Littleleaf horsebrush	Tetradymia glabrata	Hepatotoxic	Alkaloids	Shrub
Locoweed	Astragalus; Oxytropis spp	Neurological; Teratogen; Wasting	Alkaloids; Swainsonine	Forb	Early spring emergence; addictive; equines susceptible
Longspine sandbur	Cenchrus longispinus	Mouth/GI	Physical	Forb	Sandbur
Lucky nut tree	Thevetia thevetiodes	Colic/Diarrhea; Sudden Death	Glycosides	Tree	Be-still; yellow oleander
Lupine	Lupinus spp	Teratogenic; Fetal	Alkaloids; Slaframine	Forb	Young & bolting more toxic
Mad apple	Datura stramonium	Cardiac; Coma; Death	Hyoscyamine (Alkaloid)	Forb	Stinkweed; jimsonweed; Jamestown weed; thornapple
Maleberry	Lyonia ligustrina	Colic/Diarrhea; Ataxia; Depression	Arbutin	Shrub
Mallows	Malvaceae spp	See List For Nitrate Toxicosis	Nitrates	Forb	Several spp.
Marestail	Equisetum spp	Neurological	Thiaminase; Neurotoxin	Forb
Marijuana	Cannabis sativa	Neurotoxin	60 Compounds; THC	Forb	Hemp
Marsh marigold	Caltha palustris	GI Irritant; Colic/Diarrhea	Protoanemonin	Forb
Matchweed	Gutierrezia sarothrae	See List For Selenium Toxicosis	Se Accumulator	Shrub	Broomweed; turpentine weed; snakeweed; broom snakeweed
Mayapple	Podophyllum peltatum	Gastric/Diarrhea, Respiratory; Neuro	Podophyllotoxin	Forb
Meadow saffron	Colchicum autumnale	Teratogenic; Fetal	Teratogens	Forb	Autumn crocus
Medusahead rye	Taentherum asperum	Mouth/GI	Physical	Grass
Mesquite	Prosopis glandulosa	Colic/Diarrhea; Impaction	Physical Impaction	Tree	Fruits only; honey mesquite
Milkvetch	Astragalus spp	Teratogenic; ataxia; neuro; weakness	Neurotoxin; Se	Forb	Hoof abnormalities; wasting disease; several spp.
Milkweeds	Asclepias spp	Cardiac; Sudden Death; Colic	Glycosides	Forb	Under 24 hours; several spp.
Mistletoe	Phoradendron & Viscum spp.	Colic, Diarrhea, Sudden Death	Glycoproteins	Shrub	Several spp.
Monkshood	Aconitum columbianum	See Nitrate List; Gastric; Neurological	Nitrates; Alkaloids	Forb	Aconite
Morning glory	Convolvulus arvensis	Colic/Diarrhea; Cardiac	Alkaloids; Nitrates	Forb	Field bindweed
Mountain laurel	Kalmia latifolia	Colic/Diarrhea; Cardiac	Andromedotoxin	Shrub
Mountain mahogany	Cercocarpus spp.	Cardiac	Cyanide	Tree
Mountain fetterbush	Pieris spp.	Colic/Diarrhea	Acetylandromedol; Grayanotoxins	Shrub	Needles in particular
Narcissus	Narcissus spp.	Gastric/mouth, Dermatitis	Alkaloids; Narcissine	Forb	Daffodils
Needlegrass	Stipa spp	Mouth/Gastric System	Physical	Grass
Nicker tree	Gymnocladius dioica	Gastric/Diarrhea, Respiratory	Cytosine	Tree	Kentucky coffee/mahogany, American coffee, stump trees
Oak	Quercus breviloba	Colic/Diarrhea	Tannic Acid/Gallotannins	Tree	Young leaves; bark; acorns; seasonal; picas
Ohio buckeye	Aesculus glabra	GI Irritant, Hemolysis	Aesculin	Tree	New growth; leaves; nuts
Oleander	Nerium oleander	Sudden Cardiac Death; Colic/Diarrhea	Cardiac Glycosides	Shrub	Highly toxic
Onion, domestic	Allium spp	Anemia; Weakness	Alcylsulfides; Disulfides	Forb	In large quantities
Perennial ryegrass	Lolium perenne	Skin; Photosensitize	Photosensitizing Agent	Grass
Periwinkle	Vinca rosea	Teratogenic	Teratogens	Shrub
Persimmon	Diospyros virginiana	Colic/Diarrhea; Impaction	Physical	Tree	Fruits only
Philodendron	Philodendron spp	Mouth, GI Tract, Respiratory, Death	Oxalates	Browse
Pigweed	Amaranthus retroflexus	See Lists for Nitrate Toxicosis	Nitrates; Oxalates	Forb	Redroot pigweed; drought increases toxicity; oxalate list?
Pincherry	Prunus pensylvanica	Sudden Death	Cyanogenic Glycosides	Tree	Drought increases toxicity
Pingue	Hymenoxys richardsonii	GI Irritant; Photosensitization	Sesquiterpene	Forb	Colorado rubberweed; rubberweed; bitterweed
Poinsettia	Euphorbia pulcherrima	Gastric; Dermatitis; See Nitrate List	Latex, Euphorbin, Nitrates	Shrub
Poison hemlock	Conium maculatum	Death; Teratogenic	Alkaloids	Forb	All parts toxic; not in hay; chasing green in spring; 2-3 hours
Poison ivy	Toxicodendron radicans	Gastrointestinal, Dermatitis	Urushiol, Catechols	Forb
Pokeweed	Phytolacca americana	Colic/Diarrhea	Phytolaccatoxin	Forb	Entire plant toxic
Ponderosa pine	Pinus ponderosa	Abortive	Isocuppressic acid	Tree
Poppies	Papaver spp.	Teratogenic	Teratogens	Forb
Porcupine grass	Miscanthus sinensis	Mouth/GI tract	Physical	Grass
Potato	Solanum tuberosum	Colic/Diarrhea; Weakness	Alkaloids; Solanine	Forb
Prairie sagewort	Artemisia frigida	Neurological	Neurotoxin	Shrub	Fringed sage
Prairie three-awn	Aristida oligantha	Mouth/GI	Physical	Grass
Prickly pear	Opuntia spp.	Mouth/GI	Physical	Shrub
Prince's plume	Stanleya pinnata	See List For Selenium Toxicosis	Selenium	Shrub
Privets	Ligustrum vulgare	Colic/Diarrhea	Glycosides; Iridoid	Shrub	Entire plant
Puncture vine	Tribulus terrestris	Mouth/GI tract	Physical	Forb
Purple foxglove	Digitalis purpurea	Cardiac; Sudden Death	Cyanogenic Glycosides	Forb	Foxglove
Purple locoweed	Oxytropis lambertii	Neurological; Teratogen; Wasting	Alkaloids; Swainsonine	Forb	Early spring emergence; addictive; equines susceptible
Purple mint	Perilla frutescens	Respiratory	Ketones	Forb
Ragweed	Ambrosia artemesiafolia	See List For Nitrate Toxicosis	Nitrates	Forb
Rattlebox	Crotalaria spp	Weight loss; hepatotoxic; chronic	PA	Shrub	Rattlepod
Rattlepod	Crotalaria spp	Weight loss; hepatotoxic; chronic	PA	Shrub	Rattlebox
Red baneberry	Actaea rubra	Respiratory; Cardiac	Glycoside	Forb	Cohosh
Red buckeye	Aesculus pavia	GI Irritant; Muscle Weakness; Coma	Glycosides	Tree	New growth; leaves; nuts
Red clover	Trifolium pratense	Skin; Liver	Mycotoxin	Forb
Red maple	Acer rubrum	Anemia; Arrythmia; Weakness	Unknown Oxidant	Tree	Red X silver hybrids may be toxic; small amounts; dried only
Redroot pigweed	Amaranthus spp	See Lists for Nitrate Toxicosis	Nitrates; Oxalates	Forb	Pigweed; drought increases toxicity; oxalate list?
Reed canarygrass	Phalaris arundinacea	Muscular Weakness; Collapse	Alkaloids	Grass
Resinweed	Grindelia squarrosa	See List For Selenium Toxicosis	Selenium	Shrub	Curlycup gumweed
Rhododendron	Rhododendron spp.	Colic/Diarrhea; Tremors; Respiratory	Cyanide; Ursol Acid	Shrub	Also toxic when dried; azalea.
Rhubarb	Rheum rhaponticum	Gastrointestinal; Cardiovascular	Oxalates	Forb	Leaves
Richweed	Ageratina altissima	Muscular; Ataxia; Swallowing	Tremetol	Forb	White snakeroot
Riddell's ragwort	Senecio riddellii	Hepatotoxic; Weakness; Chronic	PA	Forb
Rock maple	Acer spp.	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Rosary pea	Abrus precatorius	Colic/Diarrhea; Ataxia	Lectin	Browse	See castor bean
Rubberweed	Hymenoxys richardsonii	GI Irritant; Photosensitization	Sesquiterpene	Forb	Colorado rubberweed; pingue
Russian knapweed	Acroptilon repens	Chewing Disease	Sesquiterpene; Another Unknown	Forb	Same toxin as starthistle; no cure/recovery
Russian thistle	Salsola iberica	See List For Nitrate Toxicosis	Nitrates	Forb
Sagebrush	Artemesia spp	Neurological	Monoterpenes	Forb
Saltbush	Atriplex spp	See List For Selenium Toxicosis	Selenium	Forb
Sand sage	Artemesia filifolia	Neurological; Ataxia	Volatile Oils	Forb	Sage sickness
Sandbur	Cenchrus longispinus	Mouth/GI	Physical	Forb	Longspine sandbur
Scarlet pimpernel	Anagallis arvensis	Mouth; Staggering; Ataxia	Terpenoid; Glycoside	Forb
Scotchbroom	Cytisus scoparius	Gastrointestinal; Hepatotoxic	Alkaloids	Shrub	Entire plant
Scouring rush	Equisetum arvense	Neurological; Ataxia; Blindness	Alkaloids; Thiaminase	Forb	Horsetails; snakegrass; all parts toxic; B1 may help
Sienna weed	Cassia occidentalis	Colic/Diarrhea; Ataxia; Weakness	Anthraquinone	Forb	Coffee weed
Sensitive fern	Onoclea sensibilis	Neurological; Ataxia	Thiaminase	Forb
Service berry	Amelanchier alnifolia	Death; Ataxia; Heart	Cyanogenic Glycosides	Tree	Death within minutes is possible
Shamrock	Oxalis spp	KIdney; Diarrhea/Colic	Oxalates	Forb
Shepherd's purse	Capsella bursa-pastoris	Teratogenic	Teratogens	Forb	Deformed foals
Shinnery oak	Quercus havardii	Colic/Diarrhea	Tannic Acid	Tree	Shin oak; tannins in young leaves; bark; acorns
Silver maple	Acer spp.	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Silverleaf nightshade	Solanum elaeagnifolium	Colic/Diarrhea	Alkaloids; Solanine	Forb
Skunk cabbage	Symplocarpus foetidus	Cardiovascular; Shock	Alkaloids	Forb
Smartweed	Polygonum spp	See List For Nitrate Toxicosis	Nitrates; Saponin	Forb	Entire plant
Snakegrass	Equisetum arvense; spp	Ataxia; Neurological; Blindness	Alkaloids; Thiaminase	Forb	Horsetails; scouring rush; all parts toxic; B1 may help
Snakeweed	Gutierrezia sarothrae	See List For Selenium Toxicosis	Selenium	Shrub	Turpentine weed; broom snakeweed; matchweed
Sneezeweed	Helenium hoopesii	GI Irritant	Sesquiterpene Lactone	Forb	Bitter sneezeweed
Snow on the mountain	Euphorbia marginata	Mouth/GI; Diarrhea	Esters	Forb
Soapwort	Saponaria officinalis	Gastric/Diarrhea; Depression	Saponin	Forb	Bouncing Bet
Soft maple	Acer spp.	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Sophia	Descurainia sophia	Deformed Foals	Teratogens	Forb	Flixweed, tansy mustard
Sorghum	Sorghum spp.	Cardiac; See List For Nitrate Toxicosis	Cyanogenic Glycosides; Nitrates	Grass	20 spp.; when stressed/drought; sudan grass
Sorrel	Oxalis & Rumes spp.	Kidney; Colic/Diarrhea	Oxalates	Forb
Soursob	Oxalis spp	Kidney; Colic/Diarrhea	Oxalates	Forb
Southern goldenbush	Haplopappus heterophyllus	Neurological; Muscle; Ataxia	Tremetol	Shrub	Jimmy weed; trembles
Spineless horsebrush	Tetradymia canescens	Hepatotoxic	Alkaloids	Shrub
Spiny cocklebur	Xanthium spinosum	Mouth/GI, Hepatotoxic	Glycosides; Physical	Forb
Spotted cowbane	Pastinaca sativa	Colic/Diarrhea; Photodermatitis	Coumarin	Forb	Wild parsnip
Spotted locoweed	Astragalus spp	Teratogenic; Neurological; Death	Swainsonine	Forb
Spring parsley	Cymopterus watsonii	Skin; Photosensitize	Coumarin	Forb	Photodermatitis
Squirrel corn	Dicentra cucullaria	Trembling; Diarrhea; Convulsions	Alkaloids	Forb	Dutchman's breeches; bleeding heart family
Squirreltail	Sitanion hystrix	Mouth/GI	Physical	Grass	Elymus elymoides
St. Johnswort	Hypericum perforatum	Skin; Photosensitize	Naphthodianthron; Hypericin	Forb	Klamath weed; entire skin loss
Staggergrass	Amanthium muscaetoxicum	Respiratory; Weakness; Death	Alkaloids	Grass
Star of Bethlehem	Ornithogalum umbellatum	Gastric/Diarrhea; Depression	Saponin	Forb	Entire plant
Stickseed	Hackelia & Trichodesma spp.	Weight Loss; Hepatotoxic; Chronic	PA	Forb
Stinging nettle	Urtica dioica	Mouth/GI; See List For Nitrate Toxicosis	Physical; Nitrates	Forb
Stinkweed	Datura stramonium	Teratogenic; Cardiac; Death	Hyoscyamine (Alkaloid)	Forb	Jimsonweed; mad apple; jamestown weed; thornapple
Stump tree	Gymnocladius dioica	Gastric/Diarrhea, Respiratory	Cytosine	Tree	Kentucky mahogany/coffee, American coffee, nicker trees
Sudan grass	Sorghum bicolor	Death; Ataxia; Teratogenic; Paralysis	Cyanogenic Glycosides	Grass	Drought & freeze increase toxicity
Sugar maple	Acer spp.	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Summer cypress	Kochia scoparia	Photosensitization; Hepatotoxic; Nitrate	Oxalates; Nitrates	Forb	Fireweed; kochia
Summer pheasant's eye	Adonis aestivalis	Cardiac; Colic	Adonidine	Forb
Sweet bubby	Calycanthus floridus	Tetany; Convulsions; Neurological	Calycanthin; Alkaloids	Shrub	Sweet shrub
Sweetshrub	Calycanthus floridus	Tetany; Convulsions; Neurological	Calycanthin; Alkaloids	Shrub	Sweet bubby
Tall big sagebrush	Artemisia tridentata	Neurologic	Volatile Oils	Shrub
Tall fescue	Festuca arundinacea	Abortion; Malformed Fetus	Endophytic Fungus; Alkaloids	Grass
Tanglehead	Heteropogon contortus	Mouth/GI	Physical	Grass
Tansy mustard	Descurainia sophia	Deformed Foals	Teratogens	Forb	Flixweed, sophia
Tansy ragwort	Senecio jacobaea	Hepatotoxic; Neurological	PA	Forb	Maintains toxicity in hay; equines highly susceptible
Tarweed	Amsinckia intermedia	Hepatotoxic; Weight Loss	PA	Forb	Fiddleneck
Thornapple	Datura stramonium	Teratogenic	Hyoscyamine (Alkaloid)	Forb	Jimson weed; Jamestown weed; stinkweed; mad apple
Threadleaf groundsel	Senecio douglasii	Hepatotoxic; Weakness	PA	Shrub	Woolly groundsel
Three-awn grasses	Aristida spp.	Mouth/GI	Physical	Grass
Tobacco	Nicotiana glauca	Teratogenic	Teratogens	Forb
Tomato	Lycopersicon spp.	Colic/Diarrhea; Weakness	Hyoscine	Forb
Tulip	Tulipia spp	Dermatitis; Weakness; Respiratory	Tuliposide	Forb
Tumble mustard	Sysymbrium altissimum	Teratogenic	Teratogens	Forb
Turpentine weed	Gutierrezia sarothrae	See List For Selenium Toxicosis	Selenium	Shrub	Broom snakeweed; snakeweed; matchweed
Two-grooved milkvetch	Astragalus bisculatus	See List For Selenium Toxicosis	Selenium	Forb	Freeze
Viper's bugloss	Echium vulgare	Liver Fibrosis/Failure	PA	Forb	Seeds in particular
Water hemlock	Cicuta douglasii	Tremors; Convulsions; Death	Cicutoxin	Forb	Western water hemlock; single mouthful; death in minutes
Western brackenfern	Pteridium aquilinum	Thiamin Deficiency	Thiaminase; Filicin	Browse	Bracken fern; all parts poisonous
Western chokecherry	Prunus spp	Sudden Death	Cyanogenic Glycosides	Tree
Western false hellebore	Veratrum californicum	Fetal Damage	Steroid (Alkaloids)	Forb	False hellebore; corn lily
Western water hemlock	Cicuta douglasii	Tremors; Convulsions/ Death	Cicutoxin	Forb	Water hemlock; single mouthful; death in minutes
White bryony	Bryonia cretica	Sweating; Diuresis; Convulsions	Lectine; Polyhydroxic Acids	Browse	Berries; sap; roots; worse when dried
White locoweed	Oxytropis sericea	Neurological; Teratogen; Wasting	Alkaloids; Swainsonine	Forb	Early spring emergence; addictive; equines susceptible
White maple	Acer spp.	Possibly Anemia	Unknown Oxidant	Tree
White prairie aster	Aster falcatus	See List For Selenium Toxicosis	Selenium	Forb
White snakeroot	Ageratina altissima	Muscular; Ataxia; Swallowing	Tremetol	Forb	Richweed
White sweet clover	Melilotus alba	Anemia; Hemorrhage; Weakness	Prussic Acid; Dicoumarol	Forb	When spoiled; in haylage
Wild blue flax	Linum lewisii	Ataxia; Cardiac	Glycosides	Forb	Death may occur within minutes
Wild cherry	Prunus serotina	Sudden Death	Cyanogenic Glycosides	Tree
Wild iris	Iris missouriensis	GI Irritant; Diarrhea; Dermatitis	Irisine	Forb	New growth; leaves; nuts
Wild jasmine	Cestrum diurnum	Calcinosis; Lameness/Weakness	Hyoscine	Tree	Jessamines
Wild mustard	Sinapis arvensis	Salivation; Collapse; Death	Glucosinolates	Forb
Wild oat grass	Avena fatua	See List For Nitrate Toxicosis	Nitrates	Grass	Wild oats
Wild onion	Allium spp	Anemia; Weakness	Alcylsulfides; Disulfides	Forb
Wild parsnip	Pastinaca sativa	Colic/Diarrhea; Photodermatitis	Coumarin	Forb	Spotted cowbane
Wild pea	Lathyrus latifolius	Teratogenic	Teratogens	Browse
Wild tree tobacco	Nicotiana glauca	Fetal Damage	Teratogens	Tree
Wiregrass	Eleusine indica	Gastric Distress	Alkaloids	Grass	Goosegrass
Woody aster	Xylorhiza glabriscula	See List For Selenium Toxicosis	Selenium	Shrub
Woolly groundsel	Senecio douglasii	Hepatotoxic; Weakness; Chronic	PA	Shrub	Threadleaf groundsel
Woolly locoweed	Astragalus mollismus	Neurological; Teratogen; Wasting	Alkaloids; Swainsonine	Forb	Early spring emergence; addictive; equines susceptible
Yellow bristlegrass	Setaria pumila	Mouth/GI; Foam/Drool	Physical	Grass
Yellow buckeye	Aesculus octandra	GI Irritant; Hemolysis	Aesculin	Tree
Yellow oleander	Thevetia peruviana	Colic/Diarrhea; Sudden Death	Glycosides	Shrub	Be-still; lucky nut tree
Yellow starthistle	Centaurea solstitialis	Chewing Disease	Alkaloids; Sesquiterpenes	Forb	Russian knapweed; no recovery; addictive
Yellow sweet clover	Melilotus officinalis	Anemia; Hemorrhage; Weakness	Dicoumarol	Forb	Only when spoiled and in haylage
Yellow toadflax	Linarea vulgaris	Gastric System	Glycosides	Forb	Butter and eggs
Yew	Taxus spp	Sudden Death; Neurological; Cardiac	Taxin (Alkaloid); Cyanogens	Shrub	All parts except berries; single mouthful deadly; within hours

ALPHABETICALLY BY SCIENTIFIC NAME

Scientific Name	Common Name	Area Affected	Toxin (If Known)	Type	Comments; Regional Names
Abrus precatorius	Rosary pea	Colic/Diarrhea; Ataxia	Lectin	Browse	See castor bean
Acacia & Robinia spp.	Acacia	Gastric & Nervous Systems	Glycosides; Phytotoxin	Tree	False acacia; black locust
Acer rubrum	Red maple	Anemia; Arrythmia; Weakness	Unknown Oxidant	Tree	Red X silver hybrids may be toxic; small amounts; dried only
Acer spp.	Hard maple	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Acer spp.	Rock maple	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Acer spp.	Silver maple	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Acer spp.	Soft maple	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Acer spp.	Sugar maple	Possibly Anemia	Unknown Oxidant	Tree	Possibly toxic, as with other maple spp.
Acer spp.	White maple	Possibly Anemia	Unknown Oxidant	Tree
Aconitum columbianum	Aconite	Gastric; Colic	Alkaloid Aconitine	Forb	Monkshood; not toxic when dried; used in homeopathy
Aconitum columbianum	Monkshood	See Nitrate List; Gastric; Neurological	Nitrates; Alkaloids	Forb	Aconite
Acroptilon repens	Russian knapweed	Chewing Disease	Sesquiterpene; Another Unknown	Forb	Same toxin as starthistle; no cure/recovery
Actaea rubra	Cohosh	Respiratory; Cardiac	Glycoside	Forb	Red baneberry
Actaea rubra	Red baneberry	Respiratory; Cardiac	Glycoside	Forb	Cohosh
Adonis aestivalis	Summer pheasant's eye	Cardiac; Colic	Adonidine	Forb
Aesculus californica	California buckeye	GI Irritant	Saponin; Aesculen	Tree	New growth; leaves; nuts
Aesculus glabra	Ohio buckeye	GI Irritant, Hemolysis	Aesculin	Tree	New growth; leaves; nuts
Aesculus hippocastanum	Buckeye	Neurologic; Weakness; Trembling	Saponin	Tree	All parts toxic; horse chestnut
Aesculus hippocastanum	Horse chestnut	Muscles; Ataxia	Saponin; Aesculen	Tree	All parts toxic; buckeye
Aesculus octandra	Yellow buckeye	GI Irritant; Hemolysis	Aesculin	Tree
Aesculus pavia	Red buckeye	GI Irritant; Muscle Weakness; Coma	Glycosides	Tree	New growth; leaves; nuts
Ageratina adenophora	Crofton weed	Ataxia; Muscular	Tremetol	Forb	Eupatorium adenophorum
Ageratina altissima	Richweed	Muscular; Ataxia; Swallowing	Tremetol	Forb	White snakeroot
Ageratina altissima	White snakeroot	Muscular; Ataxia; Swallowing	Tremetol	Forb	Richweed
Agrostemma githago	Corn cockle	Muscles; ataxia	Saponin	Forb	Seeds in particular
Allium spp	Onion, domestic	Anemia; Weakness	Alcylsulfides; Disulfides	Forb	In large quantities
Allium spp	Wild onion	Anemia; Weakness	Alcylsulfides; Disulfides	Forb
Amanthium muscaetoxicum	Staggergrass	Respiratory; Weakness; Death	Alkaloids	Grass
Amaranthus retroflexus	Pigweed	See Lists for Nitrate Toxicosis	Nitrates; Oxalates	Forb	Redroot pigweed; drought increases toxicity; oxalate list?
Amaranthus spp	Redroot pigweed	See Lists for Nitrate Toxicosis	Nitrates; Oxalates	Forb	Pigweed; drought increases toxicity; oxalate list?
Ambrosia artemesiafolia	Ragweed	See List For Nitrate Toxicosis	Nitrates	Forb
Amelanchier alnifolia	Service berry	Death; Ataxia; Heart	Cyanogenic Glycosides	Tree	Death within minutes is possible
Ammi majus	Bishop's weed	Photodermatitis	Coumarin	Forb	Large bullwort
Ammi majus	Large bullwort	Photodermatitis	Coumarin	Forb	Bishop's weed
Amsinckia intermedia	Tarweed	Hepatotoxic; Weight Loss	PA	Forb	Fiddleneck
Amsinckia menziesii	Fiddleneck	Hepatotoxic; Weight Loss	PA; Nitrates	Forb	Tarweed; see list for nitrate toxicosis
Anagallis arvensis	Scarlet pimpernel	Mouth; Staggering; Ataxia	Terpenoid; Glycoside	Forb
Apocynum cannabinum	Dogbane	Cardiac; Sudden Death	Cardiac Glycosides	Forb	Hemp dogbane; Indian hemp; under 24 hours
Apocynum cannabinum	Hemp dogbane	Cardiac; Sudden Death	Cardiac/Cyanogenic Glycosides	Forb	Dogbane; Indian hemp; all parts toxic
Apocynum cannabinum	Indian hemp	Cardiac; Sudden Death; Colic	Cardiac Glycosides	Forb	Dogbane; hemp dogbane; under 24 hours
Arctium minus	Burdock	Mouth/GI	Physical	Forb
Arisaema triphyllum	Jack-in-the-Pulpit	Lips/Mouth/Tongue; Salivation	Oxalates	Forb	Several spp.
Aristida oligantha	Prairie three-awn	Mouth/GI	Physical	Grass
Aristida spp.	Three-awn grasses	Mouth/GI	Physical	Grass
Artemesia filifolia	Sand sage	Neurological; Ataxia	Volatile Oils	Forb	Sage sickness
Artemesia spinescens	Budsage	Neurological	Possibly monoterpenes	Shrub
Artemesia spp	Sagebrush	Neurological	Monoterpenes	Forb
Artemisia frigida	Fringed sage	Neurological	Neurotoxin	Shrub	Prairie sagewort
Artemisia frigida	Prairie sagewort	Neurological	Neurotoxin	Shrub	Fringed sage
Artemisia tridentata	Tall big sagebrush	Neurologic	Volatile Oils	Shrub
Asclepias spp	Milkweeds	Cardiac; Sudden Death; Colic	Glycosides	Forb	Under 24 hours; several spp.
Aster falcatus	White prairie aster	See List For Selenium Toxicosis	Selenium	Forb
Astragalus bisculatus	Two-grooved milkvetch	See List For Selenium Toxicosis	Selenium	Forb	Freeze
Astragalus lentiginosus	Freckled milkvetch	Neurological	Neurotoxin	Forb
Astragalus mollismus	Woolly locoweed	Neurological; Teratogen; Wasting	Alkaloids; Swainsonine	Forb	Early spring emergence; addictive; equines susceptible
Astragalus spp	European milkvetch	Fetal Damage	Teratogens	Forb
Astragalus spp	Milkvetch	Teratogenic; ataxia; neuro; weakness	Neurotoxin; Se	Forb	Hoof abnormalities; wasting disease; several spp.
Astragalus spp	Spotted locoweed	Teratogenic; Neurological; Death	Swainsonine	Forb
Astragalus; Oxytropis spp	Locoweed	Neurological; Teratogen; Wasting	Alkaloids; Swainsonine	Forb	Early spring emergence; addictive; equines susceptible
Atriplex spp	Saltbush	See List For Selenium Toxicosis	Selenium	Forb
Avena fatua	Wild oat grass	See List For Nitrate Toxicosis	Nitrates	Grass	Wild oats
Berteroa incana	Hoary alyssum	GI; Founder; Laminitis; Edema	Unknown	Forb
Blighia sapida	Akee	Teratogenic; Fetal	Teratogens	Tree
Brassica rapa	Field mustard	Gastric/Diarrhea; Anorexia	Glucosinolates	Forb
Bromus tectorum	Cheatgrass	Mouth/Digestive Tract	Physical	Grass	Downy brome
Bromus tectorum	Downy brome	Mouth/Digestive Tract	Physical	Grass	Cheatgrass
Bryonia cretica	White bryony	Sweating; Diuresis; Convulsions	Lectine; Polyhydroxic Acids	Browse	Berries; sap; roots; worse when dried
Buxus spp.	Boxwood	Neurologic; Colic; Respiratory	Cyclobuxin (Alkaloid)	Shrub	All plant parts toxic
Caltha palustris	Marsh marigold	GI Irritant; Colic/Diarrhea	Protoanemonin	Forb
Calycanthus floridus	Sweet bubby	Tetany; Convulsions; Neurological	Calycanthin; Alkaloids	Shrub	Sweet shrub
Calycanthus floridus	Sweetshrub	Tetany; Convulsions; Neurological	Calycanthin; Alkaloids	Shrub	Sweet bubby
Cannabis sativa	Hemp	Neurotoxin	60 Compounds	Forb	Marijuana
Cannabis sativa	Marijuana	Neurotoxin	60 Compounds; THC	Forb	Hemp
Capsella bursa-pastoris	Shepherd's purse	Teratogenic	Teratogens	Forb	Deformed foals
Cassia occidentalis	Coffee weed	Lameness; Muscle Weakness	Anthraquinone	Forb	Sienna weed
Cassia occidentalis	Sienna weed	Colic/Diarrhea; Ataxia; Weakness	Anthraquinone	Forb	Coffee weed
Castilleja linariaefolia	Indian paintbrush	See List For Selenium Toxicosis	Se Accumulator	Forb
Celastrus scandens	Climbing bittersweet	Neurological; Gastric	Solanine	Browse	Nightshades
Cenchrus longispinus	Longspine sandbur	Mouth/GI	Physical	Forb	Sandbur
Cenchrus longispinus	Sandbur	Mouth/GI	Physical	Forb	Longspine sandbur
Centaurea solstitialis	Yellow starthistle	Chewing Disease	Alkaloids; Sesquiterpenes	Forb	Russian knapweed; no recovery; addictive
Cephalanthus occidentalis	Button bush	Gastrointestinal	Glycosides	Shrub
Cercocarpus spp.	Mountain mahogany	Cardiac	Cyanide	Tree
Cestrum diurnum	Jessamine, day blooming	Calcinosis; Lameness/Weakness	Hyoscine	Tree	Wild jasmine
Cestrum diurnum	Wild jasmine	Calcinosis; Lameness/Weakness	Hyoscine	Tree	Jessamines
Cestrum nocturnum	Jessamine, night blooming	Lameness/Muscle Weakness	Atropine-like Alkaloids	Tree
Chenopodium album	Lambsquarters	See List For Nitrate Toxicosis	Nitrates	Forb
Chorispora tenella	Blue mustard	Deformed Foals	Glucosinolates	Forb
Cicuta douglasii	Water hemlock	Tremors; Convulsions; Death	Cicutoxin	Forb	Western water hemlock; single mouthful; death in minutes
Cicuta douglasii	Western water hemlock	Tremors; Convulsions/ Death	Cicutoxin	Forb	Water hemlock; single mouthful; death in minutes
Cirsium arvense	Canada thistle	See List For Nitrate Toxicosis	Nitrates	Forb
Cirsium vulgare	Bull thistle	See List For Nitrate Toxicosis	Nitrates	Forb
Clematis spp.	Clematis	Colic/Diarrhea; Neurotoxic	Protoanemonin (Alkaloid)	Browse	All plant parts
Colchicum autumnale	Autumn crocus	Teratogenic; Fetal; Neurologic	Teratogens	Browse	Meadow saffron
Colchicum autumnale	Meadow saffron	Teratogenic; Fetal	Teratogens	Forb	Autumn crocus
Comandra pallida	Bastard toadflax		Se Accumulator	Forb
Conium maculatum	European hemlock	Death; Teratogenic	Teratogens; Alkaloids	Forb	Spotted/poison hemlocks; 2-3 hours
Conium maculatum	Poison hemlock	Death; Teratogenic	Alkaloids	Forb