Toxic Plants and Their Effects
Abrus precatorius (CRAB'S EYE, JEQUIRITY BEAN, PRECATORY BEAN, ROSARY PEA); seeds; gastrointestinal tract affected by toxalbumins.
Acacia spp. (CATCLAW, GUAJILLO); foliage; plant is cyanogenetic.
ACKEE (Blighia sapida); pink raphe attaching aril2 to seed, arils in immature fruit; gastrointestinal tract and nervous system affected by toxins.
Acokanthera spp. (BUSHMAN'S POISON, WINTERSWEET); seeds; cardiovascular system affected by cardiac glycosides.
ACONITE (Aconitum spp.); entire plant, esp. leaves and roots; cardiovascular system affected by alkaloid toxins.
Aconitum spp. (ACONITE, MONKSHOOD); entire plant, esp. leaves and roots; cardiovascular system affected by alkaloid toxins.
Actaea spp. (BANEBERRY, DOLL'S EYES); foliage, berries, roots; gastrointestinal tract and nervous system affected by the toxin protoanemonin.
Adenium spp. (DESERT ROSE, MOCK AZALEA); entire plant; cardiovascular system affected by digitalis-like glycosides.
Adonis spp. (PHEASANT'S EYE); entire plant; cardiovascular system affected by cardiac glycosides.
Aesculus spp. (BUCKEYES, HORSE CHESTNUT); nuts, immature growths; gastrointestinal tract affected by saponins.
Aethusa cynapium (FOOL'S PARSLEY, LESSER HEMLOCK); entire plant; gastrointestinal tract affected by alkaloid toxins.
Agave lecheguilla (LECHUGUILLA); plant is hepatogenic.
Agrostemma githago (CORNCOCKLE, PURPLECOCKLE); seeds; gastrointestinal tract affected by saponins.
Aleurites spp. (CANDLEBERRY, CANDLENUT, TUNG3 NUT, TUNG TREE); entire plant; gastrointestinal tract affected by saponins and toxalbumins.
Allamanda cathartica (ALLAMANDA, CANARIO, GOLDEN TRUMPET VINE, YELLOW ALLAMANDA); bark, leaves, fruit, seeds, sap; plant contains cathartic toxins; plant also causes dermatitis.
Allium spp. (CHIVES, GARLIC, LEEKS, ONIONS); bulbs, bulblets, flowers, stems; gastrointestinal tract affected by plant toxins.
Alocasia spp. (ELEPHANT'S EAR, TARO); leaves, stems; mouth irritated by plant raphides.
AMARANTH (Amaranthus hybridus); plant may contain toxic levels of nitrates.
Amaranthus hybridus (AMARANTH, CARELESS WEED, TUMBLEWEED); plant may contain toxic levels of nitrates.
Amaryllis spp. (AMARYLLIS, NAKED-LADY LILLY); bulbs; gastrointestinal tract affected by alkaloid toxins.
Amianthemum muscaetoxicum (FLY-POISON, STAGGERGRASS); leaves, underground parts of plant; alkaloid toxins may cause respiratory failure.
Ammi majus (BISHOP'S WEED); plant may contain toxic levels of nitrates.
Amsinckia intermedia (FIDDLENECK, TARWEED); seed-like nutlets; plant may contain toxic levels of nitrates.
Anemone spp. (includes Pulsatilla spp.) (ANEMONE, PASQUE FLOWER, WINDFLOWER); entire plant; gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.
ANGEL TRUMPET TREE (Brugmansia x candida); entire plant, esp. seeds; nervous system affected by belladonna alkaloids; plant contains hallucinogens.
Aplopappus spp. (GOLDENRODS, JIMMY WEED, RAYLESS); leaves; plant may contain toxic levels of nitrates.
Apocynum spp. (DOGBANE, INDIAN HEMP, SPREADING DOGBANE); leaves; plant contains cardiac glycosides.
APPLES (Malus spp.); seeds; plant is cyanogenetic.
APRICOTS (Prunus spp.); seeds; plant is cyanogenetic.
Aquilegia vulgaris (COLUMBINE); entire plant; cardiovascular system affected by plant toxins.
Areca catechu (ARECA PALM, BETEL NUT); entire plant.
ARECA PALM (Areca catechu); entire plant.
Argemone spp. (MEXICAN POPPY, PRICKLY POPPY); entire plant; isoquinoline alkaloid causes "epidemic dropsy" in humans.
Arisaema spp. (GREEN DRAGON, INDIAN TURNIP, JACK-IN-THE-PULPIT); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
Arnica Montana (ARNICA); rhizomes, flowers; gastrointestinal tract and cardiovascular system affected by plant toxins; plant also causes dermatitis.
ARROWGRASS (Triglochim maritima); leaves; plant is cyanogenetic.
Arum spp. (CUCKOO-PINT, ITALIAN ARUM, LORDS & LADIES); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
Asclepias spp. (MILKWEEDS, WHORLED BUTTERFLY); leaves, stems; plant contains toxic resins.
Astragalus (LOCOWEEDS, POISON-VETCHES); entire plant; plant may absorb toxic levels of selenium.
Atropa belladonna (BELLADONNA, DEADLY NIGHTSHADE); entire plant; nervous system affected by the alkaloids jasciamine, atropine, and belladonnin.
AUTUMN CROCUS (Colchicum autumnale, other Colchicum spp.); entire plant; gastrointestinal tract affected by the toxin colchicine and other alkaloids; plant also causes dermatitis.
Avena sativa (OATS); plant is nontoxic unless contaminated with smut or fungi.
AZALEAS (Rhododendron spp.); leaves, nectar; cardiovascular system affected by the resinoid andromedotoxin.
BAGPOD (Sesbania spp.); seeds; gastrointestinal tract affected by saponins.
Bahia oppositifolia (BAHIA); entire plant; plant is cyanogenetic.
BALSAM APPLE (Momordica balsamina); outer rind of ripe fruit, seeds; gastrointestinal tract affected by toxalbumins.
BALSAM PEAR (Momordica charantia); outer rind of ripe fruit, seeds; gastrointestinal tract affected by toxalbumins.
BANEBERRY (Actaea spp.); berries, roots; gastrointestinal tract and nervous system affected by the toxin protoanemonin.
BARILLA (Halogeton glomeratus); leaves, stems; plant contains soluble oxalates.
BARNYARD GRASS (Echinochloa crusgalli); plant may contain toxic levels of nitrates.
BEAD TREE (Melia azedarach); fruit, bark; plant contains convulsants.
BEGGAR-TICK (Bidens frondosa); plant may contain toxic levels of nitrates.
BELLADONNA (Atropa belladonna); entire plant; nervous system affected by the alkaloids jasciamine, atropine, and belladonnin.
BELLYACHE BUSH (Jatropha gossypiifolia); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
BERMUDA BUTTERCUP, BERMUDA OXALIS (Oxalis pes-caprae); leaves; plant contains soluble oxalates.
Beta vulgaris (MANGOLD, SUGAR BEET); leaves; plant contains soluble oxalates and may contain toxic levels of nitrates.
Bidens frondosa (BEGGAR-TICK); plant may contain toxic levels of nitrates.
BINDWEED (Ipomea spp.); entire plant; plant contains LSD-related hallucinogens and may contain toxic levels of nitrates.
BIRD-OF-PARADISE (Caesalpinia gilliesii); seeds; gastrointestinal tract affected by plant toxins.
BIRDSFOOT TREFOIL (Lotus corniculatus); entire plant; plant is cyanogenetic.
BISHOP'S WEED (Ammi majus); plant may contain toxic levels of nitrates.
BITTER GOURD (Momordica charantia); outer rind of ripe fruit, seeds; gastrointestinal tract affected by toxalbumins.
BITTERSWEET (Celastrus scandens; do not confuse with Solanum dulcamara); entire plant; plant is reputed to be toxic.
BITTERWEED (Helenium spp.); plant causes dermatitis.
BLACK BRUSH (Flourensia cernua); fruit; gastrointestinal tract affected by plant toxins.
BLACK BRYONY (Tamus communis); toxic principles similar to Bryonia dioica.
BLACK LOCUST (Robinia pseudoacacia); bark, seeds, leaves; gastrointestinal tract affected by toxalbumins.
BLACK NIGHTSHADE (Solanum nigrum); leaves, berries; gastrointestinal tract affected by solanin glycoalkaloids; plant also causes dermatitis.
BLEEDING HEART (Dicentraformosa); entire plant, esp. bulbs; plant contains convulsants including isoquinoline; plant also causes dermatitis.
Blighia sapida (ACKEE); pink raphe1 attaching aril2 to seed, arils in immature fruit; toxins affect gastrointestinal tract and nervous system.
BLOODROOT (Sanguinaria canadensis); juices from stems and rootstocks cause dermatitis.
BLUEBONNETS (Litpinus subcarnosus); leaves, esp. seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.
BLUE RUSH (Juncus inflexus); plant causes convulsions in cattle.
BLUE TARO (Xanthosoma spp.); leaves; mouth irritated by plant raphides; plant also causes dermatitis.
BOUNCING BET (Saponaria officinalis); seeds; gastrointestinal tract affected by saponins.
BOX, BOXWOOD (Buxus sempervirens); entire plant; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
BRACKEN FERN, BRAKE FERN (Pteridium sp.); fronds; plant contains thiaminase.
Brassica spp. (CABBAGE, KALE, MUSTARD); leaves; plant is goitrogenic; may contain toxic levels of nitrates; B. napus (CULTIVATED RAPE) is hepatogenic.
Bromus spp. (RESCUE GRASS, SMOOTH BROMEGRASS); plant may contain toxic levels of nitrates.
BROOMCORN (Sorghum sp.); leaves; plant is cyanogenetic.
Brugmansia x candida (ANGEL TRUMPET TREE); entire plant, esp. seeds; nervous system affected by belladonna alkaloids; plant contains hallucinogens.
Bryonia dioica (DEVIL'S TURNIP, WHITE BRYONY); gastrointestinal tract affected by the glycosides bryonin and bryonidin; plant also causes dermatitis.
BUCKEYES (Aesculus spp.); nuts, immature growths; gastrointestinal tract affected by saponins.
BUCKTHORN (Karwinskia humboldtiana - do not confuse with the mildly toxic Rhamnus spp.); fruit; toxins affect nervous system.
BUCKWHEAT (Fagopyrum esculentum); plant causes photosensitization and contact dermatitis.
BUFFALO BUR (Solanum sp.); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; plant may contain toxic levels of nitrates; also causes dermatitis.
BULL NETTLE (Solanum sp.); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; plant may contain toxic levels of nitrates; also causes dermatitis.
BUNCH-GRASS (Nolina texana); foliage; hepatogenic.
BUR CLOVER (Medicago denticulata); plant causes photosensitization.
BURNING BUSH (Euonymus spp.); fruit; cardiovascular system affected by the glycosides evobioside, evomonoside, and evonoside.
BUSHMAN'S POISON (Acokanthera spp.); seeds; cardiovascular system affected by cardiac glycosides.
BUTTERCUPS (Ranunculus spp.); sap; toxin, protoanemonin, affects gastrointestinal tract and nervous system; plant also causes dermatitis.
BUTTONBUSH (Cephalanthus occidentalis); entire plant, esp. leaves.
Buxus sempervirens (BOX, BOXWOOD); entire plant; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
CABBAGE (Brassica sp.); leaves; plant is goitrogenic.
CACTI (numerous genera); certain species are toxic.
Caesalpina gilliesii (BIRD-OF-PARADISE); seeds: gastrointestinal tract affected by plant toxins.
Caladium spp. (CALADIUM, also see Xanthosoma spp.); leaves; mouth irritated by plant raphides.
CALEY PEA (Lathyrus spp.); stems, seeds; nervous system affected by plant toxins.
CALICO BUSH (Kalmia sp.); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by the toxins andromedotoxin and arbutin.
CALIFORNIA CHICORY (Rafinesquia californica).: plant may contain toxic levels of nitrates.
CALLA LILY (Zantedeschia aethiopica); leaves; mouth irritated by plant raphides.
Calotropis spp. (CROWN FLOWER); entire plant; cardiovascular system affected by cardiac glycosides.
Caltha palustris (COWSLIP, MARSH MARIGOLD); entire plant; gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.
CALTROP (Tribulus terrestris); plant may contain toxic levels of nitrates; plant is also hepatogenic.
CALYCANTH (Calycanffius spp.); seeds; cardiovascular and nervous systems affected by plant toxins.
Calycanthus spp. (CALYCANTH, CAROLINA ALLSPICE); seeds; cardiovascular and nervous systems affected by plant toxins.
Campsis spp. (TRUMPET VINE); plant causes dermatitis.
CANADA THISTLE (Cirsium arvense); plant may contain toxic levels of nitrates.
CANARIO (Allamanda cathartica); bark, leaves, fruit, seeds, sap; plant contains cathartic toxins; plant also causes dermatitis.
CANDLEBERRY, CANDLENUT (Aleurites molluccana); entire plant; gastrointestinal tract affected by saponins and toxalbumins.
Cannabis sativa (MARIJUANA); leaves, flower bracts; plant contains the hallucinogens tetrahydro-cannabinols.
CARDINAL FLOWER (Lobelia spp.); leaves, stems, fruit; nervous system affected by the toxin pyridine; plant also causes dermatitis.
Carduus sp. (PLUMELESS THISTLE); plant may contain toxic levels of nitrates.
CARELESS WEED (Amaranthus hybridus); plant may contain toxic levels of nitrates.
CAROLINA ALLSPICE (Calycanthus spp.); seeds; cardiovascular and nervous systems affected by plant toxins.
CASSAVA (Manihot esculenta); leaves, esp. roots; plant is cyanogenetic.
Cassia spp. (COFFEE SENNA, GOLDEN SHOWER, INDIGO, SENNA, SICKLE POD); entire plant; gastrointestinal tract affected by toxalbumins.
CASTOR BEAN (Ricinus communis); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
CATCLAW (Acacia greggi); foliage, plant is cyanogenetic.
CELANDINE, CELANDINE POPPY (Chelidonium majus); entire plant; nervous system affected by the alkaloids chelidonine, chelerithrine, and protopine; plant also causes dermatitis.
Celastrus scandens (BITTERSWEET); entire plant; plant is reputed to be toxic.
Cephalanthus occidentalis (BUTTONBUSH); entire plant, esp. leaves; plant is reputed to be toxic.
Cercocarpus montanus (MOUNTAIN-MAHOGANY); wilted leaves; plant is cyanogenetic.
Cestrum spp. (DAY-BLOOMING JESSAMINE, JASMINE, NIGHT-BLOOMING JESSAMINE); fruit, sap; gastrointestinal tract affected by solanine glycoalkaloids; nervous system affected by atropine-like toxins.
CHEESEWEED (Malva parviflora); plant may contain toxic levels of nitrates.
Chelidonium majus (CELANDINE, CELANDINE POPPY); entire plant; nervous system affected by the alkaloids chelidonine, chelerithrine, and protopine; plant also causes dermatitis.
Chenopodium spp. (GOOSEFOOT, LAMB'S QUARTERS, PIGWEED, WORMSEED); plant may contain toxic levels of nitrates.
CHERRIES (Prunus spp.); kernels in pits; plant is cyanogenetic.
CHERRY LAUREL (Prunus sp.); entire plant; plant is cyanogenetic.
CHICKWEED (Stellaria media); plant may contain toxic levels of nitrates.
CHINABERRY TREE (Melia azedarach); fruit, bark; plant contains convulsants.
CHINESE LANTERN (Physalis spp.); unripe berries; gastrointestinal tract affect by solanine glycoalkaloids.
CHIVES (Allium spp.); bulbs, bulblets, flowers, stems; toxins affect gastrointestinal tract; plant also causes dermatitis.
CHRISTMAS-BERRY (Heteromeles artbutifolia); leaves; plant is cyanogenetic.
CHRISTMAS ROSE (Helleborus niger); entire plant; cardiovascular system affected by the cardiac glycosides helleborin and helleborein; plant also causes dermatitis.
Cicuta spp. (WATER HEMLOCK); entire plant, esp. roots; nervous system affected by the convulsant cicutoxin.
Cirsium arvense (CANADA THISTLE); plant may contain toxic levels of nitrates.
Claviceps spp. (ERGOT); an ascomycetous fungus which grows on small grain (e.g., rye); also contains the alkaloid indole.
Clematis spp. (CLEMATIS, TRAVELLER'S JOY, VIRGIN'S BOWER); entire plant; gastrointestinal tract and nervous system affected by plant toxins; plant also causes dermatitis.
Cleome serrulata (ROCKY MT. BEE PLANT); plant may contain toxic levels of nitrates.
CLIMBING LILY (Gloriosa spp.); entire plant, esp. tubers; gastrointestinal tract affected by the toxin colchicine.
CLOVERS (Trifolium spp.); plant causes photosensitization and contact dermatitis (also see WHITE CLOVER).
COAL-OIL BRUSH (Teradymia glabrata); leaves; plant is hepatogenic.
COAST GOLDENBUSH (Haplopappus venetus); plant may contain toxic levels of nitrates.
COCKLEBUR (Xanthium orientate); leaves at sprouted two-leaf stage, germinating seeds; plant contains hydroquinone; also causes dermatitis.
COFFEE SENNA (Cassia occidentalis); entire plant; gastrointestinal tract affected by toxalbumins.
COFFEEWEED (Sesbania spp.); seeds; gastrointestinal tract affected by saponins.
Colchicum autumnale (AUTUMN CROCUS, MEADOW SAFFRON); entire plant; gastrointestinal tract affected by the toxin colchicine and other alkaloids; plant also causes dermatitis.
Colocasia esculenta (ELEPHANT'S EAR, TARO); leaves; mouth irritated by plant raphides.
COLUMBINE (Aquilegia vulgaris); entire plant; cardiovascular system affected by plant toxins.
COMMON LANTANA (Lantana camara); immature berries; nervous system affected by the atropine-like toxin lantodene; plant is also hepatogenic.
COMMON PRIVET (Ligustrum vulgare); entire plant; gastrointestinal tract affected by the glycoside ligustrin.
COMMON VETCH (Vicia sativa); seeds, moldy parts; plant is cyanogenetic; plant also causes photosensitization.
Conium maculatum (HEMLOCK, POISON HEMLOCK); entire plant, esp. roots and seeds; nervous system affected by alkaloids including coniine, coniceine, and conidrine; may contain toxic levels of nitrates; plant also causes dermatitis.
Convallaria majalis (LILY-OF-THE-VALLEY); entire plant; cardiovascular system affected by the glycosides convallarin and convallamarin.
COONTIE (Zamia pumila); roots, trunk; gastrointestinal tract and nervous system affected by plant toxins.
COPPERWEED (Oxytenia acerosa); leaves; toxic principle unknown.
CORAL PLANT (Jatropha multifida); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
Coriaria myrtifolia (no trivial name in U.S.); fruit; plant contains convulsants.
CORNCOCKLE (Agrostemma githago); seeds; gastrointestinal tract affected by saponins.
Corydalis spp. (FITWEED); entire plant; plant contains convulsants including isoquinoline.
Corynocarpus laevigatus (no trivial [common] name in U.S.);fruit; plant contains convulsants.
COWCOCKLE (Saponaria vaccaria); seeds; gastrointestinal tract affected by saponins.
COWSLIP (Caltha palustris); entire plant; gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.
COYOTILLO (Karawinskia humboldtiana); fruit; nervous system affected by plant toxins.
CRAB'S EYE (Abrus precatorius); seeds; gastrointestinal tract affected by toxalbumins.
CREEPING CHARLIE (Glechoma hederacea); plant contains a variety of volatile oils.
Crotalaria spp. (RATTLEBOX); entire plant; pyrrolizidine alkaloids cause hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
CROWFOOTS (Ranunculus spp.); gastrointestinal tract and nervous system affected by the toxin protoanemonin; plant also causes dermatitis.
CROWNBEARD (Verbesina encelioides); plant may contain toxic levels of nitrates.
CROWN FLOWERS (Calotropis spp.) entire plant; cardiovascular system affected by cardiac glycosides.
Crytostegia spp. (RUBBER VINE, PURPLE ALLAMANDA); entire plant; cardiovascular system affected by digitalis-like glycoside.
CUCKOO-PINT (Arum maculatum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
CULTIVATED RAPE (Brassica napus); plant is hepatogenic.
CURCAS BEAN (Jatropha curcas); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
Cypripedium spp. (LADY SLIPPER, MOCCASIN FLOWER, SHOWY LADY SLIPPER, YELLOW LADY SLIPPER); plant causes dermatitis.
Cytisus scoparious (SCOTCH BROOM); seeds; plant contains quinolizidine alkaloid toxins.
DAFFODIL (Narcissus spp.); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.
Daphne spp. (DAPHNE, MEZEREON, SPURGE LAUREL, WOOD LAUREL); entire plant, esp. fruit and seeds; gastrointestinal tract and kidneys affected by coumarin glycosides; plant also causes dermatitis.
Datura stramonium (DEVIL'S TRUMPET, JIMSON WEED, THORNAPPLE); entire plant; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine; may contain toxic levels of nitrates; plant also causes dermatitis.
DAY-BLOOMING JESSAMINE (Cestrum diurnum); fruit, sap; gastrointestinal tract affected by solanine glycoalkaloids; nervous system affected by atropine-like toxins.
DEADLY NIGHTSHADE (Atropa belladonna); entire plant; nervous system affected by the alkaloids jasciamine, atropine, and belladonnin.
DEATH CAMAS (Zigadenus spp.); entire plant; cardiovascular system affected by alkaloid toxins.
Delphinium spp. (LARKSPUR); cardiovascular system affected by alkaloids including delphinine; plant also causes dermatitis.
DESERT ROSE (Adenium spp.); entire plant; cardiovascular system affected by digitalis-like glycosides.
DEVIL'S CLUB (Echinopanax horridum); plant causes dermatitis.
DEVIL'S TRUMPET (Datura stramonium); entire plant; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine; may contain toxic levels of nitrates; plant also causes dermatitis.
DEVIL'S TURNIP (Bryonia dioica); gastrointestinal tract affected by the glycosides bryonin and bryonidin; plant also causes dermatitis.
Dicentra spp. (BLEEDING HEART, DUTCHMAN'S BREECHES, GOLDEN EAR-DROPS, SQUIRREL CORN, STAGGER WEED, STEER'S HEAD); entire plant, esp. bulbs; plant contains convulsants including isoquinoline; plant also causes dermatitis.
Dieffenbachia spp. (DUMBCANE); leaves; mouth irritated by plant raphides; plant also causes dermatitis.
Digitalis purpurea (FOXGLOVE, PURPLE FOXGLOVE);
entire plant; cardiovascular system affected by the glycosides digitalin and digitoxin; gastrointestinal tract affected by saponins.
Dionaea sp. (VENUS FLYTRAP); entire plant.
DOCKS (Rumex spp.); leaves; plant contains soluble oxalates and may contain toxic levels of nitrates: plant also causes dermatitis.
DOGBANE (Apocynum cannabinum); plant contains cardiac glycosides.
DOG HOBBLE (Leucothoe spp.); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.
DOLL'S EYES (Actaea spp.); foliage, berries, roots; gastrointestinal tract and nervous system affected by the toxin protoanemonin.
DUMBCANE (Dieffenbachia spp.); leaves; mouth irritated by plant raphides; plant also causes dermatitis.
DUTCHMAN'S BREECHES (Dicentra cucullaria); entire plant, esp. bulbs; plant contains convulsants including isoquinoline; plant also causes dermatitis.
EAGLE FERN (Pteridium sp.); fronds; plant contains thiaminase.
Echinochloa crusgalli (BARNYARD GRASS); plant may contain toxic levels of nitrates.
Echinopanax horridum (DEVIL'S CLUB); plant causes dermatitis.
Echium vulgare (VIPER'S BUGLOSS); entire plant; pyrrolizidine alkaloid causes hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
ELDERBERRY (Sambucus spp.); entire plant; plant is cyanogenetic and may contain toxic levels of nitrates.
ELEPHANT'S EAR (Alocasia sp., Colocasia esculenta); leaves, stems; mouth irritated by plant raphides.
ENGLISH IVY (Hedera helix); berries, leaves; gastrointestinal tract affected by saponins; plant also causes dermatitis.
Equisetum spp. (FOXTAILS, HORSETAILS, SCOURING RUSH); stems; toxic principles uncertain; fungus growing on plant may cause toxicity.
ERGOT (Claviceps spp.); an ascomycetous fungus which grows on small grain (e.g., rye); also contains the alkaloid indole.
Eriobotrya japonica (LOQUAT, JAPAN PLUM); kernel in pit; plant is cyanogenetic.
Euonymus spp. (BURNING BUSH, SPINDLE TREE, STRAWBERRY BUSH, WAHOO); fruit; cardiovascular system affected by the glycosides evobioside, evomonoside, and evonoside.
Eupatorium spp. (JOE-PYE WEED, THOROUGHWORT, WHITE SNAKEROOT); leaves; plant may contain toxic levels of nitrates.
Euphorbia spp. (EUPHORBIA, MILK BUSH, POINSETTIA, SNOW-ON-THE-MOUNTAIN, SPURGES); latex; gastrointestinal tract affected by the toxin euphorbin; may contain toxic levels of nitrates; plant also causes dermatitis.
EUROPEAN BEECH (Fagus sylvatica); seeds; gastrointestinal tract affected by saponins.
EUROPEAN MISTLETOE (Viscum album); leaves, stems; gastrointestinal tract affected by toxalbumins.
Fagopyrum spp. (BUCKWHEAT, INDIA WHEAT); plant causes photosensitization and contact dermatitis.
Fagus sylvatica (EUROPEAN BEECH); seeds; gastrointestinal tract affected by saponins.
FALSE HELLEBORE (Veratrum spp.); entire plant; cardiovascular system affected by alkaloid toxins; plant also causes dermatitis.
FALSE JESSAMINE (Gelsemium sempervirens); leaves, roots; plant contains convulsants including indole; plant also causes dermatitis.
FALSE SAGO PALM (Zamia pumila); trunk, roots; gastrointestinal tract and nervous system affected by plant toxins.
FANWEED (Thlaspi arvensi); seeds; gastrointestinal tract affected by mustard oil.
FESCUE, TALL (Festuca arundinacea); considered nontoxic unless contaminated with ERGOT (Claviceps sp.) or other fungi.
Festuca arundinacea (FESCUE, TALL); considered nontoxic unless contaminated with ERGOT (Claviceps sp.) or other fungi.
FETTERBUSH (Pieris spp.); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.
FIDDLENECK (Amsinckia intermedia); seed-like nutlets; plant may contain toxic levels of nitrates.
FIREBALL (Kochia scoparia; plant may contain toxic levels of nitrates.
FITWEED (Corydalis spp.); entire plant; plant contains convulsants including isoquinoline.
FLAG (Iris spp.); rootstocks; toxins affect gastrointestinal tract; plant also causes dermatitis.
FLAX (Linum usitatissimus); entire plant, esp. immature seed pods; plant is cyanogenetic and goitrogenic; may contain toxic levels of nitrates.
Florensia cernua (BLACK BRUSH, TARBUSH); fruit; gastrointestinal tract affected by plant toxins.
Florestina tripteris (FLORESTINA); entire plant; plant is cyanogenetic.
FLORIDA ARROWROOT (Zamia pumila); trunk, roots; gastrointestinal tract and nervous system affected by plant toxins.
FLY-POISON (Amianthemum muscaetoxicum); leaves, underground parts of plant; alkaloids cause respiratory failure.
FOOL'S PARSLEY (Aethusa cynapium); entire plant; gastrointestinal tract affected by alkaloid toxins.
FOUR O'CLOCK (Mirabilis sp.); entire plant; gastrointestinal tract affected by the alkaloid trigonelline.
FOWL MANNAGRASS (Glyceria striate); entire plant; plant is cyanogenetic.
FOXGLOVE (Digitalis purpurea); entire plant; cardiovascular system affected by the glycosides digitalin and digitoxin; gastrointestinal tract affected by saponins.
FOXTAILS (Equisetum spp.); stems; toxic principles uncertain; fungus growing on plant may cause toxicity.
FRIJOLITO (Sophora secundiflora); seeds; nervous system affected by nicotine-like, quinolizidine alkaloids.
Fritillaria meleagris (SNAKE'S HEAD BULB); cardiovascular system affected by alkaloid toxins.
Galanthus nivalis (SNOWDROP); gastrointestinal tract affected by the alkaloids lycorine and galantamine.
GARLIC (Allium spp.); bulbs, bulblets, flowers, stems; gastrointestinal tract affected by plant toxins.
Gelsemium sempervirens (FALSE JESSAMINE, YELLOW JESSAMINE); flowers, leaves, roots; plant contains convulsants including indole; plant also causes dermatitis.
GILL-OVER-THE-GROUND (Glechoma hederacea); plant contains a variety of volatile oils.
Glechoma hederacea (CREEPING CHARLIE, GILLOVER-THE-GROUND, GROUND IVY); plant contains a variety of volatile oils.
Gloriosa spp. (CLIMBING LILY, GLORIOSA LILY, GLORY LILY); entire plant, esp. tubers; gastrointestinal tract affected by the toxin colchicine.
GLORY LILY (Gloriosa spp.); entire plant, esp. tubers; gastrointestinal tract affected by the toxin colchicine.
Glyceria striata (FOWL MANNAGRASS); entire plant; plant is cyanogenetic.
Glycine max (SOYBEAN); plant is goitrogenic and may contain toxic levels of nitrates.
GOATHEAD (Tribulus terrestris); plant is hepatogenic and may contain toxic levels of nitrates.
GOAT WEED (Hypericum perforatum); entire plant; plant causes photosensitization and contact dermatitis.
GOLDENCHAINTREE (Laburnum x watereri); entire plant, esp. seeds; nervous system affected by the alkaloid cytisine.
GOLDEN EAR-DROPS (Dicentra chrysantha); entire plant, esp. bulbs; plant contains convulsants including isoquinoline; plant also causes dermatitis.
GOLDENRODS (Aplopappus spp.); leaves; plant may contain toxic levels of nitrates.
GOLDEN SHOWER (Cassia fistula); pulp of pods, leaves, bark; plant contains cathartic toxins.
GOLDEN TRUMPET VINE (Allamanda cathartica); bark, leaves, fruit, seeds, sap; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
GOLDENWEEDS (Oonopsis spp.); entire plant; plant may absorb toxic levels of selenium.
GOOSEFOOT (Chenopodium glaucum); plant may contain toxic levels of nitrates.
GOOSEGRASS (Triglochin maritima); leaves; plant is cyanogenetic.
GOUT STALK (Jatropha podagrica); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
GREASEWOOD (Sarcobatus vermiculatus); plant contains soluble oxalates; also causes dermatitis.
GREEN DRAGON (Arisaema dracontium); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
GROUND CHERRY (Physalis spp.); unripe berries; gastrointestinal tract affected by solanine glycoalkaloids.
GROUND IVY (Glechoma hederacea); plant contains a variety of volatile oils.
GROUNDSEL (Senecio spp.); entire plant; pyrrolizidine alkaloid causes hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
GUAJILLO (Acacia ber landieri); foliage; plant is cyanogenetic.
Gymnocladus dioicus (KENTUCKY COFFEE TREE); seeds; nervous system affected by nicotine-like toxins.
Halogeton glomeratus (BARILLA, HALOGETON); leaves, stems; plant contains soluble oxalates.
Haplopappus venetus (COAST GOLDENBUSH); plant may contain toxic levels of nitrates.
Hedera helix (ENGLISH IVY); berries, leaves; gastrointestinal tract affected by saponins; plant also causes dermatitis.
Helenium spp. (BITTERWEED, PINGUE, RUBBERWEED, SNEEZEWEED); plant causes dermatitis.
Helianthus annuus (WILD ARTICHOKE, WILD SUNFLOWER); plant may contain toxic levels of nitrates.
HELIEBORE (Ranunculus spp.); sap; gastrointestinal tract and nervous system affected by the toxin protoanemonin; plant also causes dermatitis.
HELIOTROPE (Heliotropium spp.); entire plant; pyrrolizidine alkaloid causes hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
Heliotropium spp. (HELIOTROPE); entire plant; pyrrolizidine alkaloid causes hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
HELLEBORE (Helleborus niger); entire plant; cardiovascular system affected by the glycosides helleborin and helleborein; plant also causes dermatitis.
Helleborus niger (CHRISTMAS ROSE, HELLEBORE); entire plant; cardiovascular system affected by the glycosides helleborin and helleborein; plant also causes dermatitis.
HEMLOCK (Conium maculatum); entire plant, esp. roots and seeds; nervous system affected by the alkaloids coniine, conidrine, and coniceine; may contain toxic levels of nitrates; plant also causes dermatitis.
HENBANE (Hyoscyamus niger); seeds; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine.
Heteromeles artbutifolia (CHRISTMAS-BERRY); leaves; plant is cyanogenetic.
HIGUERETA (Ricinus communis); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
Hippobroma longiflora (HORSE POISON, MADAM FATA); entire plant; plant contains convulsants.
Hippomane mancinella (MANCHINEEL); latex; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
Holcus lanatus (VELVET GRASS, MESQUITE GRASS); fresh or wilted plant; plant is cyanogenetic.
HOLLY (Ilex spp.); berries; gastrointestinal tract affected by saponins.
HONEYSUCKLE BUSH (Lonicera spp); berries; gastrointestinal tract, cardiovascular and nervous systems affected by plant toxins.
HORSEBEAN (Parkinsonia aculeata); plant may contain toxic levels of nitrates.
HORSEBRUSH (Tetradymia glabrata); leaves; plant is hepatogenic.
HORSE CHESTNUT (Aesculus sp.); nuts, immature growths; gastrointestinal tract affected by saponins.
HORSE NETTLE (Solanum sp.); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.
HORSE POISON (Hipponbroma longiflora); entire plant; plant contains convulsants.
HORSETAILS (Equisetum spp.); stems; toxic principles uncertain; fungi growing on plant may cause toxicity.
Hura crepitans (MONKEY PISTOL, JAVILLO, SANDBOX TREE); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
HYACINTH (Hyacinthus orientalis); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.
Hyacinthus orientalis (HYACINTH); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.
Hydrangea spp. (HYDRANGEA); flower buds; plant is cyanogenetic; plant also causes dermatitis.
Hyoscyamus niger (HENBANE); seeds; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine.
Hypericum perforatum (GOAT WEED, KLAMATH WEED, ST. JOHNSWORT); entire plant; plant causes photosensitization and contact dermatitis.
Ilex spp. (HOLLY, YAUPON); berries; gastrointestinal tract affected by saponins.
INDIAN HEMP (Apocynum cannabinum); leaves; plant contains cardiac glycosides.
INDIAN KALE (Xanthosoma spp.); leaves; mouth affected by irritant raphides; plant also causes dermatitis.
INDIAN POKE (Veratrum sp.); entire plant; cardiovascular system affected by alkaloid toxins; plant also causes dermatitis.
INDIAN TOBACCO (Lobelia inflata); leaves, stems, fruit; nervous system affected by pyridine, a nicotine-like toxin; plant also causes dermatitis.
INDIAN TURNIP (Arisaema triphyllum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
INDIA WHEAT (Fagopyrum tataricum); plant causes photosensitization.
INDIGO (Cassia sp.); entire plant; gastrointestinal tract affected by toxalbumins.
Ipomea spp. (BINDWEED, MORNING GLORIES, SWEET POTATO VINES); entire plant; plant contains LSD-related hallucinogens; may contain toxic levels of nitrates.
Iris spp. (IRIS, FLAG); rootstocks; gastrointestinal tract affected by the glycoside iridin; plant also causes dermatitis.
ITALIAN ARUM (Arum italicum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
JACK-IN-THE-PULPIT (Arisaema triphyllum, other species); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
JAPANESE LANTERN (Physalis spp.); unripe berries; gastrointestinal tract affected by solanine glycoalkaloids.
JAPAN PLUM (Eriobotrya japonica); kernel in pit; plant is cyanogenetic.
JASMINE (Cestrum spp.); fruit, sap; gastrointestinal tract affected by solanine glycoalkaloids; nervous system affected by atropine-like toxins.
Jatropha spp. (BELLYACHE BUSH, CORAL PLANT, CURCAS BEAN, GOUT STALK, JICAMILLA, PEREGRINA, PHYSIC NUT, PURGE NUT); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
JAVA BEAN (Phaseolus lunatus); entire plant; plant is cyanogenetic.
JAVILLO (Hura crepitans); seeds; gastrointestinal tract affected by toxalbumins, plant also causes dermatitis.
JEQUIRITY BEAN (Abrus precatorius); seeds; gastrointestinal tract affected by toxalbumins.
JERUSALEM CHERRY (Solanum pseudocapsicum); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.
JETBEAD (Rhodotypos scandens); berries; plant is reputed to contain a cyanogenic glycoside.
JICAMILLA (Jatropha spp.); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils, plant also causes dermatitis.
JIMMY WEED (Aplopappus heterophyllus); leaves; plant may contain toxic levels of nitrates.
JIMSON WEED (Datura stramonium); entire plant; nervous system affected by the alkaloids atropine,scopolamine, and hyoscyamine; may contain toxic levels of nitrates; plant also causes dermatitis.
JOE-PYE WEED (Eupatorium sp.); plant may contain toxic levels of nitrates.
JOHNSON GRASS (Sorghum halepense); leaves; plant is cyanogenetic.
JONQUIL (Narcissus sp.); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.
Juncus inflexus (BLUE RUSH); plant causes convulsions in cattle.
KALE (Brassica sp.); leaves; plant is goitrogenic.
Kalmia spp. (CALICO BUSH, LAMBKILL, MOUNTAIN LAUREL, SHEEP LAUREL); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by the toxins andromedotoxin and arbutin.
Karwinskia humboldtiana (BUCKTHORN, COYOTILLO); fruit; nervous system affected by plant toxins.
KENTUCKY COFFEE TREE (Gymnocladus dioicus); seeds; nervous system affected by nicotinelike toxins.
KLAMATH WEED (Hypericum perforatum); entire plant; plant causes photosensitization and contact dermatitis.
Kochia scoparia (FIREBALL, MEXICAN FIREWOOD, SUMMER CYPRESS); plant may contain toxic levels of nitrates.
LABRADOR TEA (Ledum spp.); leaves; plant contains toxic resins.
Labumum x watereri (GOLDENCHAINTREE, LABURNUM); entire plant, esp. seeds; nervous system affected by cytisine, a nicotine-like alkaloid.
Lactuca sariola (PRICKLY LETTUCE); plant may contain toxic levels of nitrates.
LADY SLIPPER (Cypripedium spectabiles); plant causes dermatitis.
LADY'S THUMB (Polygonum persicaria); plant may contain toxic levels of nitrates; plant also causes photosensitization and contact dermatitis.
LAMBKILL (Kalmia augustifolia); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by andromedotoxin and arbutin.
LAMB'S QUARTERS (Chenopodium album); plant may contain toxic levels of nitrates.
Lantana camara (COMMON LANTANA); immature berries; nervous system affected by lantodene, an atropine-like toxin; plant is also hepatogenic.
LARKSPUR (Delphinium spp.); leaves; cardiovascular system affected by alkaloids including delphinine; plant also causes dermatitis.
Lathyrus spp. (CALEY PEA, SINGLETARY PEA, SWEET PEA, VETCHLING, WILD PEA); stems, seeds; nervous system affected by plant toxins.
LAUREL (Rhododendron spp.); leaves; cardiovascular system affected by the resinoid andromedotoxin.
LECHUGUILLA (Agave lecheguilla); plant is hepatogenic.
Ledum spp. (LABRADOR TEA); leaves; plant contains toxic resins.
LEEK (Allium tricoccum); bulbs, bulblets, flowers, stems; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
LESSER HEMLOCK (Aethusa cynapium); entire plant; gastrointestinal tract affected by alkaloid toxins.
Leucothoe spp. (DOG HOBBLE, PEPPER BUSH, SWEET BELLS, WHITE OSIER); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.
Ligustrum vulgare (COMMON PRIVET, PRIVET); entire plant; gastrointestinal tract affected by the glycoside ligustrin.
LILY-OF-THE-FIELDS (Anemone spp.); entire plant; gastrointestinal tract affected by the toxin protoanemonin.
LILY-OF-THE-VALLEY (Convallaria majalis); entire plant; cardiovascular system affected by the glycosides convallarin and convallamarin.
LIMA BEAN (Phaseolus lunatus); entire plant; plant is cyanogenetic.
LINSEED (Linum usitatissimus); entire plant, esp. immature seed pods; plant is cyanogenetic and goitrogenic.
Linum spp. (FLAX, LINSEED, YELLOW PINE FLAX); entire plant, esp. immature seed pods; plant is cyanogenetic. FLAX and LINSEED (L. usitatissimus) may contain toxic levels of nitrates, and plants are goitrogenic. YELLOW PINE FLAX (L. neomexicanum) contains saponins which affect gastrointestinal tract.
Lobelia spp. (CARDINAL FLOWER, LOBELIA, INDIAN TOBACCO); leaves, stems, fruit; nervous system affected by pyridine, a nicotine-like toxin; plant also causes dermatitis.
LOCOWEEDS (Astragalus spp., Oxytropis spp.); entire plant; may absorb toxic levels of selenium.
Lonicera spp. (HONEYSUCKLE BUSH); berries; gastrointestinal tract, cardiovascular and nervous systems affected by plant toxins.
LOQUAT (Eriobotrya japonica); kernel in pit; plant is cyanogenetic.
LORDS & LADIES (Arum maculatum); entire plant; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides; plant also causes dermatitis.
Lotus corniculatus (BIRDSFOOT TREFOIL); entire plant; plant is cyanogenctic.
LUPINES (Lupinus spp.); leaves, esp. seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.
Lupinus spp. (BLUEBONNETS, LUPINES, PURSH, SILKY LUPINE); leaves, esp. seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.
Lycium spp. (MATRIMONY VINE); leaves; gastrointestinal tract affected by plant toxins.
Lycospersicon esculentum (TOMATO); vines, suckers; gastrointestinal tract affected by solanine glycoalkaloids.
Lygodesmia juncea (SKELETONWEED); plant may contain toxic levels of nitrates.
MADAM FATE (Hippobroma longiflora); entire plant; plant contains convulsants.
MALANGA (Xanthosoma spp.); leaves; mouth affected by irritant raphides; plant also causes dermatitis.
MALLOW (Malva parviflora); plant mav contain toxic levels of nitrates.
Malus spp. (APPLES); seeds; plant is cyanogenetic.
Malva parviflora (CHEESEWEED, MALLOW); plant may contain toxic levels of nitrates.
MANCHINEEL (Hippomane mancinella); latex; toxins affect gastrointestinal tract; plant also causes dermatitis.
Mandragora officinarum (MANDRAKE); nervous system affected by the toxins hyoscyamine and mandragorin.
MANDRAKE (Mandragora officinarum); nervous system affected by the toxins hyoscyamine and mandragorin.
MANGOLD (Beta vulgaris); leaves; plant contains soluble oxalates; may contain toxic levels of nitrates.
Manihot esculenta (CASSAVA); leaves, esp. Roots; plant is cyanogenetic.
MARIJUANA (Cannabis sativa); leaves, flower bracts; plant contains the hallucinogens tctrahydro-cannabinols.
MARSH MARIGOLD (Caltha palustris); entire plant, gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.
MARVEL OF PERU (Mirabilis jalapa); entire plant; gastrointestinal tract affected by the alkaloid tri gonelline; plant also causes dermatitis.
MATRIMONY VINE (Lycium spp.); leaves; gastrointestinal tract affected by plant toxins.
MAY APPLE (Podophyllum peltatum); entire plant except fruit; nervous system affected by plant toxins; also cause hematological abnormalities; powdered root may cause conjunctivitis and keratitis.
MEADOW BRAKE (Onoclea sensibilis); leaves; nervous system affected by plant toxins.
MEADOW SAFFRON (Colchicum autumnale); entire plant; gastrointestinal tract affected by colchicine and other alkaloids; plant also causes dermatitis.
Medicago denticulata (BUR CLOVER); plant causes photosensitization.
Melia azedarach (BEAD TREE, CHINABERRY TREE, PRIDE-OF-INDIA); fruit, bark; plant contains convulsants.
Melilotus spp. (WHITE OR YELLOW SWEETCLOVERS); plant may contain toxic levels of nitrates.
Menispermum canadense (MOONSEED); fruit; plant contains convulsants.
Menziesia ferruginea (RUSTYLEAF); leaves; plant contains toxic resins.
MESCAL BEAN (Sophora secundiflora); seeds; nervous system affected by the nicotine-like, quinolizidine alkaloids.
MESQUITE GRASS (Holcus lanatus); fresh or wilted plant; plant is cyanogenetic.
Metopium toxiferum (POISON WOOD); plant causes dermatitis.
MEXICAN FIREWOOD (Kochia scoparia); plant may contain toxic levels of nitrates.
MEXICAN POPPY (Argemone mexicana); entire plant; isoquinoline alkaloid causes "epidemic dropsy" in humans.
MEZEREON (Daphne mezereum); entire plant, esp. fruit and seeds; gastrointestinal tract and kidneys affected by coumarin glycosides; plant also causes dermatitis.
MILK BUSH (Euphorbia spp.); latex; gastrointestinal tract affected by the toxin euphorbin; may contain toxic levels of nitrates; plant also causes dermatitis.
MILKWEEDS (Asclepias spp.); leaves, stems; plant contains toxic resins.
MINER'S LETTUCE (Montia perfoliata); plant may contain toxic levels of nitrates.
Mirabilis jalapa (FOUR O'CLOCK, MARVEL OF PERU); entire plant; gastrointestinal tract affected by the alkaloid trigonelline; plant also causes dermatitis.
MISTLETOES (Phoradendron spp.); leaves, stems, berries; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
MOCCASIN FLOWER (Cypripedium spectabiles); plant causes dermatitis.
MOCK AZALEA (Adenium spp.); entire plant; cardiovascular system affected by digitalis-like glycosides.
MOCK ORANGE (Poncirus trifoliata); fruit; gastrointestinal tract affected by plant toxins.
Momordica spp. (BALSAM APPLE, BALSAM PEAR, BITTER GOURD, WHITE BALSAM APPLE); seeds; gastrointestinal tract affected by toxalbumins.
MONKEY PISTOL (Hura crepitans); seeds; gastrointestinal tract affected by toxalbumins.
MONKEY POD (Samonia samon); gastrointestinal tract affected by saponins; plant also causes dermatitis.
MONKSHOOD (Aconitum spp.); entire plant, esp. leaves and roots; cardiovascular svstem affected by alkaloid toxins.
Montia perfoliata (MINER'S LETTUCE); plant may contain toxic levels of nitrates.
MOONSEED (Menispermum canadense); fruit; plant contains convulsants.
MORNING GLORIES (Ipomea spp.); entire plant; plant contains LSD-related hallucinogens; may contain toxic levels of nitrates.
MOUNTAIN LAUREL (Kalmia latifolia); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by the toxins andromedotoxin and arbutin.
MOUNTAIN-MAHOGANY (Cercocarpus montanus); wilted leaves; plant is cyanogenetic.
MUSHROOMS (many wild varieties); see appropriate literature for toxicities.
MUSTARD (Brassica sp.); leaves; plant is goitrogenic; may contain toxic levels of nitrates.
Myoporum laetum (no trivial [common] name in U.S.); fruit, esp.leaves; plant contains convulsants.
NAKED-LADY LILY (Amaryllis sp.); bulbs; gastrointestinal tract affected by alkaloid toxins.
Narcissus spp. (DAFFODIL, JONQUIL); bulbs; gastrointestinal tract affected by alkaloid toxins; plant also causes dermatitis.
Nerium oleander (OLEANDER); entire plant, and water used for cut plants; cardiovascular system affected by the glycosides oleandrin, oleandroside, and nerioside; plant also causes dermatitis.
NETTLE (Urtica procera); plant may contain toxic levels of nitrates.
Nicotiana spp. (TOBACCO, TREE TOBACCO); leaves; nervous system affected by the alkaloids nicotine and pyridine.
NIGHT-BLOOMING JESSAMINE (Cestrum nocturnum); fruit, sap; gastrointestinal tract affected by solanine glycoalkaloids; nervous system affected by atropine-like toxins.
NIGHTSHADES (Solanum spp.); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.
Nolina texana (BUNCH GRASS, SACAHUISTA); foliage; plant is hepatogenic.
NUX-VOMICA TREE (Strychnos nux-vomica); entire plant; nervous system affected by the alkaloid strychnine.
OAKS (Quercus spp); buds, leaves; oak tannin causes gastritis and nephritis.
OATS (Avena saliva); nontoxic unless contaminated with smut or fungi.
Oenanthe crocata (WATER DROPWORT); entire plant; plant contains the convulsant oenanthetoxin.
OLEANDER (Nerium oleander, other species); entire plant, and water used for cut plants; cardiovascular system affected by the glycosides oleandrin, oleandroside, and nerioside; plant also causes dermatitis.
ONION (Allium cepa); bulbs, bulblets, flowers, stems; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
Onoclea sensibilis (MEADOW BRAKE, POLYPODY BRAKE, SENSITIVE FERN); leaves; nervous system affected by plant toxins.
Oonopsis spp. (GOLDENWEEDS); entire plant; plant may absorb toxic levels of selenium.
OPIUM POPPY (Papaver somniferum); unripe seedpods; plant contains a wide variety of alkaloids including morphine, codeine, papaverine, narcotine, and isoquinoline.
Ornithogalum spp. (STAR-OF-BETHLEHEM, WONDER FLOWER); entire plant, esp. bulbs; gastrointestinal tract affected by alkaloid toxins.
Oxalis pes-caprae (BERMUDA BUTTERCUP, BERMUDA OXALIS, SORREL, SOURSOB); leaves; plant contains soluble oxalates.
Oxytenia acerosa (COPPERWEED); leaves; toxic principle unknown.
Oxytropis spp. (LOCOWEEDS, POINT VETCH); entire plant; plant is reputed to be toxic.
Panicum capillare (PANIC-GRASS, WITCHGRASS); plant is hepatogenic; may contain toxic levels of nitrates.
Papaver somniferum (OPIUM POPPY); unripe seedpods; plant contains a wide variety of alkaloids including morphine, codeine, papaverine, narcotine, and isoquinoline.
Parkinsonia aculeata (HORSEBEAN); plant may contain toxic levels of nitrates.
PASQUE FLOWER (Anemone spp.; includes Pulsatilla spp.); entire plant; gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.
Pastinaca sativa (WILD PARSNIP); plant causes dermatitis.
PEACE LILY (Spathyphyllum spp.) entire plant; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
PEACH (Prunus spp.); seeds; plant is cyanogenetic.
Pedilanthus tithymaloides (SLIPPER FLOWER); latex; gastrointestinal tract affected by plant toxins.
PEPPER BUSH (Leucothoe spp.); leaves, nectar; cardiovascular and nervous systems affected.
PEREGRINA (Jatropha integerrima); seeds; gastrointestina! tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
PERIWINKLE (Vinca spp.); entire plant; plant contains hallucinogens.
Pernettya spp. (no trivial names in U.S.); leaves, nectar; cardiovascular system affected by plant toxins.
Phaseolus lunatus (JAVA BEAN, LIMA BEAN); entire plant; plant is cyanogenetic.
PHEASANT'S EYE (Adonis spp.); entire plant; cardiovascular system affected by cardiac glycosides.
Philodendron spp. (PHILODENDRON); leaves; mouth irritated by plant raphides.
Phoradendron spp. (MISTLETOES); leaves, stems, berries; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
Physalis spp. (CHINESE LANTERN, GROUND CHERRY, JAPANESE LANTERN, POHA); unripe berries; gastrointestinal tract affected by solanine glycoalkaloids.
PHYSIC NUT (Jatropha curcas); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
Phytolacca americans (PIGEONBERRY, POKEBERRY, POKEWEED); leaves, roots; gastrointestinal tract affected by saponins.
Pieris spp. (FETTERBUSH); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.
PIGEONBERRY (Phytolacca americans); all parts, esp. roots; gastrointestinal tract affected by saponins.
PIG-LILLY (Zantedeschida spp.); leaves; mouth irritated by plant raphides.
PIGWEED (Chenopodium spp.); entire plant; may contain toxic levels of nitrates.
PINGUE (Helenium spp.); plant causes dermatitis.
Plagiobothrys sp. (POPCORN FLOWER); plant may contain toxic levels of nitrates.
PLUM (Prunus spp.); seeds; plant is cyanogenetic.
PLUMELESS THISTLE (Carduus sp.); plant may contain toxic levels of nitrates.
Podophyllum peltatum (MAY APPLE); entire plant except fruit; plant toxins affect nervous system and cause hematological abnormalities; powdered root may cause conjunctivitis and keratitis.
POHA (Physalis spp.); unripe berries; gastrointestinal tract affected by solanine glycoalkaloids.
POINSETTIA (Euphorbia pulcherrima); latex; gastrointestinal tract affected by the toxin euphorbin, may contain toxic levels of nitrates; plant also causes dermatitis.
POINT VETCH (Oxytropis spp.); entire plant; plant is reputed to be toxic.
POISON HEMLOCK (Conium maculatum); entire plant, esp. roots and seeds; nervous system affected by alkaloids including coniine, conidrine, and coniceine; may contain toxic levels of nitrates; plant also causes dermatitis.
POISON IVY (Toxicodendron radicans); leaves, bark, and fruit cause dermatitis.
POISON OAK (Toxicodendron spp.); leaves, bark, and fruit cause dermatitis.
POISON SUCKLEYA (Suckleya suckleyana); leaves; plant is cyanogenetic.
POISON SUMAC (Toxicodendron vernix); leaves, bark, and fruit cause dermatitis.
POISONVETCHES (Astragalus spp.); entire plant: may absorb toxic levels of selenium.
POISON WOOD (Metopium toxiferum); plant causes dermatitis.
POKEBERRY, POKEWEED (Phytolacca americans); leaves, roots; gastrointestinal tract affected by saponins.
Polygonum spp. (LADY'S THUMB, SMARTWEEDS); plant may contain toxic levels of nitrates; also causes photosensitization and contact dermatitis.
POLYPODY BRAKE (Onoclea sensibilis); leaves; nervous system affected by plant toxins.
Poncirus trifoliata (MOCK ORANGE, TRIFOLIATE ORANGE); fruit; gastrointestinal tract affected by plant toxins.
POPCORN FLOWER (Plagiobothrys sp.); plant may contain toxic levels of nitrates.
POTATO (Solanum tuberosum); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.
PRECATORY BEAN (Abrus precatorius); seeds; gastrointestinal tract affected by toxalbumins.
PRICKLY LETTUCE (Latuca sariola); plant may contain toxic levels of nitrates.
PRICKLY POPPY (Argemone mexicana); entire plant; isoquinoline toxin causes "epidemic dropsy" in humans.
PRIDE-OF-INDIA (Melia azedarach); fruit, bark; plant contains convulsants.
PRIMROSE (Primula spp.); leaves cause dermatitis.
Primula spp. (PRIMROSE); leaves cause dermatitis.
PRINCESS'S PLUME (Stanleya pinnata); entire plant; may absorb toxic levels of selenium.
PRIVET (Ligustrum vulgare); entire plant; gastrointestinal tract affected by the glycoside ligustrin.
Prunus spp. (APRICOT, CHERRY, CHERRY LAUREL, PLUM, PEACH); seeds; plant is cyanogenetic.
Ptelea baldwinii (WAFER ASH); plant causes photosensitization and contact dermatitis.
Pteridium spp. (BRACKEN FERN, BRAKE FERN, EAGLE FERN); fronds; plant contains thiaminase.
PUNCTURE VINE (Tribulus terrestris); plant is hepatogenic; may contain toxic levels of nitrates.
PURGE NUT (Jatropha spp.); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils: plant also causes dermatitis.
PURPLE ALLAMANDA (Cryptostegia sp.); entire plant; cardiovascular system affected by digitalislike glycosides.
PURPLECOCKLE (Agrostemma githago); seeds; gastrointestinal tract affected by saponins.
PURPLE FOXGLOVE (Digitalis purpurea); entire plant; cardiovascular system affected by the glycosides digitalin and digitoxin; gastrointestinal tract affected by saponins.
PURSH (Lupinus sp.); leaves, esp. seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.
QUEEN'S DELIGHT (Stillingia treculeana); leaves, stems; plant is cyanogenetic.
Quercus spp. (OAKS); buds, leaves; oak tannin causes gastritis and nephritis.
Rafinesquia californica (CALIFORNIA CHICORY); plant may contain toxic levels of nitrates.
RAGWORT (Senecio jacobaea); entire plant; pyrrolizidine alkaloids cause hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
RAIN TREE (Samonia samon); gastrointestinal tract affected by saponins; plant also causes dermatitis.
Ranunculus spp. (BUTTERCUPS, CROWFOOTS, HELIEBORE); sap; gastrointestinal tract and nervous system affected by the toxin protoanemonin; plant also causes dermatitis.
RATTLEBOX (Crotalaria sp.); entire plant; pyrrolizidine alkaloids cause hepatic veno-occlusive disease (Budd-Chiari syndrome) in humans.
RATTLEBUSH, RATTLEBOX (Sesbania spp.); seeds; gastrointestinal tract affected by saponins.
RAYLESS (Aplopappus heterophyllus); leaves; plant may contain toxic levels of nitrates.
RED PUCCOON (Sanguinaria canadensis); juices from stems and rootstocks cause dermatitis.
RED SQUILL (Urginea maritima); bulbs; cardiovascular system affected by cardiac glycosides.
RESCUE GRASS (Bromus sp.); plant may contain toxic levels of nitrates.
Rhamnus spp. (BUCKTHORN, also see Karwinskia humboldtiana); fruit, bark; gastrointestinal tract affected by plant toxins.
Rheum rhaponticum (RHUBARB); leaf blades; plant contains cathartic toxins, including oxalic acid.
Rhododendron spp. (AZALEAS, LAUREL, RHODODENDRON); leaves; cardiovascular system affected by the resinoid andromedotoxin.
Rhodotypos scandens (JETBEAD); berries; plant is reputed to contain a cyanogenic glycoside.
RHUBARB (Rheum rhaponticum); leaf blades; plant contains cathartic toxins including oxalic acid.
RICINO (Ricinus communis); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
Ricinus communis (CASTOR BEAN, HIGUERETA, RICINO); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
Rivina humilis (ROUGE PLANT); leaves, roots; gastrointestinal tract affected by plant toxins.
Robinia pseudoacacia (BLACK LOCUST); bark, seeds, leaves; gastrointestinal tract affected by toxalbumins.
ROCKY MOUNTAIN BEE PLANT (Cleome serrulata); plant may contain toxic levels of nitrates.
ROSARY PEA (Abrus precatorius); seeds; gastrointestinal tract affected by toxalbumins.
ROUGE PLANT (Rivina humilis); leaves, roots; gastrointestinal tract affected by toxalbumins.
RUBBER VINE (Cryptostegia sp.); entire plant; cardiovascular system affected by digitalis-like glycosides.
RUBBERWEED (Helenium spp.); plant causes dermatitis.
RUE (Ruta graveolens); gastrointestinal tract affected by the toxins furocoumarins, tannins, and xantotoxins; plant also causes photosensitization.
Rumex spp. (DOCKS, SHEEP SORREL); leaves; plant contains soluble oxalates; may contain toxic levels of nitrates; plant also causes dermatitis.
RUSTYLEAF (Menziesia ferruginea); leaves; plant contains toxic resins.
Ruta graveolens (RUE); gastrointestinal tract affected by the toxins furocoumarins, tannins, and xantotoxins; plant also causes photosensitization.
SACAHUISTA (Nolina texana); foliage; plant is hepatogenic.
SAGE (Salvia reflexa); leaves of certain varieties contain toxic levels of nitrates.
Salvia reflexa (SAGE); leaves of certain varieties contain toxic levels of nitrates.
Sambucus spp. (ELDERBERRY); entire plant; plant is cyanogenetic; may contain toxic levels of nitrates.
Samonia samon (MONKEY POD, RAIN TREE); gastrointestinal tract affected by saponins; plant also causes dermatitis.
SANDBOX TREE (Hura crepitans); seeds; gastrointestinal tract affected by toxalbumins; plant also causes dermatitis.
Sanguinaria canadensis (BLOODROOT, RED PUCCOON); juices from stems and rootstocks cause dermatitis.
Saponaria spp. (BOUNCING BET, COWCOCKLE); seeds; gastrointestinal tract affected by saponins.
Sarcobatus vermiculatus (GREASEWOOD); plant contains soluble oxalates; also causes dermatitis.
SCARLET PIMPERNEL (Anagallis arvensis); leaves; plant causes dermatitis.
SCOTCH BROOM (Cytisus scoparious); seeds; plant contains quinolizidine alkaloid toxins.
SCOURING RUSH (Equisetum spp.); stems; toxic principles unknown; fungi growing on plants may cause toxicity.
SEA ONION (Urginea maritima); bulbs; cardiovascular system affected by cardiac glycosides.
Senecio spp. (GROUNDSEL, RAGWORT); entire plant; pyrrolizidine alkaloids cause hepatic venoocclusive disease (Budd-Chiari syndrome) in humans.
SENNA (Cassia occidentalis); entire plant: plant contains cathartic toxins.
SENSITIVE FERN (Onoclea sensibilis); leaves; nervous system affected by plant toxins.
Sephora secundiflora (FRIJOLITO, MESCAL BEAN); seeds; nervous system affected by nicotine-like quinolizidine alkaloids.
Sesbania spp. (BAGPOD, COFFEEWEED, RATTLEBOX, RATTLEBUSH); seeds; gastrointestinal tract affected by saponins.
SHEEP LAUREL (Kalmia augustifolia); leaves, nectar; gastrointestinal tract, cardiovascular and nervous systems affected by the toxins andromedotoxin and arbutin.
SHEEP SORREL (Rumex acetosella); leaves; plant contains soluble oxalates; may contain toxic levels of nitrates; plant also causes dermatitis.
SHOWY LADY SLIPPER (Cypripedium reginae); plant causes dermatitis.
SICKLEPOD (Cassia sp.); entire plant; gastrointestinal tract affected by toxalbumins.
SILKY LUPINE (Lupinus spp.); leaves, esp. Seeds; plant contains numerous alkaloid toxins including quinolizidine and piperidine.
Silybum marianum (VARIEGATED THISTLE); plant may contain toxic levels of nitrates.
SINGLETARY PEA (Lathyrus spp.); stems, seeds; nervous system affected by the plant toxins.
SKELETONWEED (Lygodesmia juncea); plant may contain toxic levels of nitrates.
SKUNK CABBAGE (Symplocarpus foetidus); leaves; gastrointestinal tract affected by plant toxins.
SLIPPER FLOWER (Pedilanthus tithymaloides); latex; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides.
SMARTWEEDS (Polygonum spp.); plant may contain toxic levels of nitrates; plant causes photosensitization and contact dermatitis.
SMOOTH BROMEGRASS (Bromus sp.); plant may contain toxic levels of nitrates.
SNAKE'S HEAD (Fritillaria meleagris); bulb; cardiovascular system affected by alkaloid toxins.
SNEEZEWEED (Helenium spp.); plant causes dermatitis.
SNOWBERRY (Symphoricarpos albus); gastrointestinal tract affected by saponins; plant also causes dermatitis.
SNOWDROP (Galanthus nivalis); gastrointestinal tract affected by the alkaloids lycorine and galantamine.
SNOW-ON-THE-MOUNTAIN (Euphorbia marginata); latex; gastrointestinal tract affected by the toxin euphorbin; may contain toxic levels of nitrates; plant also causes dermatitis.
Solanum spp. (BITTERSWEET, BUFFALO BUR, BULL NETTLE, HORSE NETTLE, JERUSALEM CHERRY, NIGHTSHADES, POTATO); immature growths; gastrointestinal tract affected by solanine glycoalkaloids; may contain toxic levels of nitrates; plant also causes dermatitis.
Sonchus spp. (SOW THISTLE); plant may contain toxic levels of nitrates.
Sophora secundiflora (FRIJOLITO, MESCAL BEAN); seeds; nervous system affected by nicotine-like, quinolizidine alkaloids.
Sorghum spp. (BROOMCORN, JOHNSON GRASS, SORGHUM, SUDAN GRASS); leaves; plant is cyanogenetic; may contain toxic levels of nitrates.
SORRELS (Oxalis pes-caprae, Rumex spp.); leaves; plant contains soluble oxalates; plant also causes dermatitis.
SOURGRASS (Triglochin maritima); leaves; plant is cyanogenetic.
SOURSOB (Oxalis pes-caprae); leaves; plant contains soluble oxalates. SOW THISTLE (Sonchus spp.); plant may contain toxic levels of nitrates.
SOYBEAN (Glycine max); may contain toxic levels of nitrates; plant is goitrogenic.
SPATHE FLOWER (Spathiphyllum spp.); entire plant; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
Spathiphyllum spp. (SPATHE FLOWER, WHITE ANTHURIUM); entire plant; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
Spigelia spp. (WEST INDIAN PINKROOT); entire plant; nervous system affected by the toxin spigeline.
SPINDLE TREE (Euonymus europaeus); fruit; cardiovascular system affected by the glycosides evobioside, evomonoside, and evonoside.
SPINELESS HORSEBRUSH (Tetradymia canescens); leaves, buds; plant causes photosensitization.
SPREADING DOGBANE (Apocynum androsaemifolium); leaves; plant contains cardiac glycosides.
SPRING RABBITBUSH (Tetradymia glabrata); leaves, buds; plant is hepatogenic.
SPURGE LAUREL (Daphne laureola); entire plant, esp. fruit and seeds; gastrointestinal tract and kidneys affected by coumarin glycosides; plant also causes dermatitis.
SPURGE NETTLE (Jatropha spp.); seeds; gastrointestinal tract affected by toxalbumins and cathartic oils; plant also causes dermatitis.
SPURGES (Euphorbia spp.); leaves, stems, latex; gastrointestinal tract affected by the toxin euphorbin; may contain toxic levels of nitrates; plant also causes dermatitis.
SQUILL (Urginea maritima); bulbs; cardiovascular system affected by cardiac glycosides.
SQUIRREL CORN (Dicentra cucullaria); entire plant, esp. bulbs; plant contains convulsants including isoquinoline; plant also causes dermatitis.
STAGGERGRASS (Amianthemum muscaetoxicum); leaves, underground parts; alkaloids cause respiratory failure.
STAGGER WEED (Dicentra cucullaria); entire plant, esp. bulbs; plant contains convulsants including isoquinoline; plant also causes dermatitis.
Stanleya pinnata (PRINCES'S PLUME); entire plant; plant may absorb toxic levels of selenium.
STAR-OF-BETHLEHEM (Omithogalum umbellatum); entire plant, esp. bulbs; gastrointestinal tract affected by alkaloid toxins.
STEER'S HEAD (Dicentra uniflora); entire plant, esp. bulbs; plant contains convulsants including isc,quinoline; plant also causes dermatitis.
Stellaria media (CHICKWEED); plant may contain toxic levels of nitrates.
Stillingia treculeana (QUEEN'S DELIGHT); leaves, stems; plant is cyanogenetic.
ST. JOHNSWORT (Hypericum perforatum); entire plant causes photosensitization and contact dermatitis.
STRAWBERRY BUSH (Euonymus americanus); fruit; cardiovascular system affected by the glycosides evobioside, evomonoside, and evonoside.
STRYCHNINE (Strychnos nux-vomica); entire plant; nervous system affected by the alkaloid strychnine.
Strychnos nux-vomica (NUX-VOMICA TREE, STRYCHNINE); entire plant; nervous system affected by the alkaloid strychnine.
Suckleya suckleyana (POISON SUCKLEYA); leaves; plant is cyanogenetic.
SUDAN GRASS (Sorghum sp.); leaves; plant is cyanogenetic; may contain toxic levels of nitrates.
SUGAR BEET (Beta vulgaris); leaves; plant contains soluble oxalates; may contain toxic levels of nitrates.
SUMMER CYPRESS (Kochia scoparia); plant may contain toxic levels of nitrates.
SWEET BELLS (Leucothoe spp.); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.
SWEETCLOVERS; WHITE, YELLOW (Melilotus spp.); plant may contain toxic levels of nitrates.
SWEET PEA (Lathyrus spp.); stems, seeds; nervous system affected by plant toxins.
SWEET POTATO VINES (Ipomea spp.); entire plant; plant contains LSD-related hallucinogens. may contain toxic levels of nitrates.
Symphoricarpus albus (SNOWBERRY); gastrointestinal tract affected by saponins; plant also causes dermatitis.
Symplocarpus foetidus (SKUNK CABBAGE); leaves; gastrointestinal tract affected by plant toxins; mouth irritated by plant raphides.
Tamus communis (BLACK BRYONY); toxic principles similar to Bryonia dioica.
Tanacetum vulgare (TANSY); leaves, stems; plant toxins may cause gastritis and convulsions; plant also causes dermatitis.
TANSY (Tanacetum vulgare); leaves, stems; plant toxins may cause gastritis and convulsions; plant also causes dermatitis.
TARBUSH (Flourensia cernua); fruit; gastrointestinal tract affected by plant toxins.
TARO (Alocasis sp., Colocasia esculenta): leaves, stems; mouth irritated by plant raphides.
TARWEED (Amsinckia intermedia); seed-like nutlets; plant may contain toxic levels of nitrates.
Taxus spp. (YEWS); entire plant, except red aril; gastrointestinal tract and cardiovascular system affected by volatile oils, and the alkaloids taxine and ephedrine.
Tetradymia glabrata (COAL-OIL BRUSH, HORSEBRUSH, SPRING RABBITBUSH); leaves: plant is hepatogenic.
Thevetia peruviana (YELLOW-BE-STILL-TREE, YELLOW OLEANDER); entire plant, esp. seeds; cardiovascular system affected by cardiac glycosides.
Thlaspi arvensi (FANWEED); seeds; gastrointestinal tract affected by mustard-oil.
THORNAPPLE (Datura stramonium); entire plant; nervous system affected by the alkaloids atropine, scopolamine, and hyoscyamine; may contain toxic levels of nitrates; plant also causes dermatitis.
THOROUGHWORT (Eupatorium sp.); plant may contain toxic levels of nitrates.
TOBACCO, TREE TOBACCO (Nicotiana spp.); leaves; nervous system affected by the alkaloids nicotine and pyridine.
TOMATO (Lycospersicon evculentum); vines. suckers: gastrointestinal tract affected by solanine glycoalkaloids.
Toxicodendron spp. (POISON IVY, POISON OAK, POISON SUMAC); leaves, bark and fruit cause dermatitis.
TRAVELLER'S JOY (Clematis spp.); entire plant; gastrointestinal tract and nervous system affected by plant toxins; plant also causes dermatitis.
TREFOIL (Lotus corniculatus); entire plant; plant is cyanogenetic.
Tribulus spp. (CALTROP, GOATHEAD, PUNCTURE VINE); plant is hepatogenic; may contain toxic levels of nitrates.
TRIFOLIATE ORANGE (Poncirus trifoliata); fruit; toxins affect gastrointestinal tract.
Trifolium spp. (CLOVERS); plant causes photosensitization and contact dermatitis; T repens (WHITE CLOVER) is cyanogenetic.
Triglochin maritima (ARROWGRASS, GOOSEGRASS, SOURGRASS); leaves; plant is cyanogenetic.
Triticum aestivum (WHEAT); nontoxic unless contaminated with fungi.
TRUMPET VINE (Campsis spp.); leaves, flowers; plant also causes dermatitis.
Tulipa spp. (TULIPS); bulbs; plant causes dermatitis.
TUMBLEWEED (Amaranthus hibridus); plant may contain toxic levels of nitrates.
TUNG NUT1, TUNG TREE (Aleurites fordii); entire plant; gastrointestinal tract affected by saponins and toxalbumins.
Urechites lutea (YELLOW NIGHTSHADE); leaves; cardiovascular system affected by the cardiac glycoside urechitoxin.
Urginea maritima (RED SQUILL, SEA ONION, SQUILL); bulbs; cardiovascular system affected by cardiac glycosides.
Urtica procera (NETTLE); plant may contain toxic levels of nitrates.
VELVET GRASS (Holcus lanatus); entire plant; plant is cyanogenetic.
VENUS FLYTRAP (Dionaea sp.); entire plant.
Veratrum spp. (FALSE HELLEBORE, INDIAN POKE); entire plant; cardiovascular system affected by alkaloid toxins; plant also causes dermatitis.
Verbesina encelioides (CROWNBEARD); plant may contain toxic levels of nitrates.
VETCH (Vicia spp.); seeds, moldy parts; plant causes photosensitization.
VETCHLING (Lathyrus spp.); seeds, stems; nervous system affected by plant toxins.
Vicia sativa (COMMON VETCH); seeds, moldy parts; plant is cyanogenetic; plant also causes photosensitization.
Vinca spp. (PERIWINKLE); entire plant; contains hallucinogens.
VIPER'S BUGLOSS (Echium plantagineum); entire plant; pyrrolizidine alkaloids cause hepatic venoocclusive disease (Budd-Chiari syndrome) in humans.
VIRGIN'S-BOWER (Clematis sp.); entire plant; gastrointestinal tract and nervous system affected by plant toxins; plant also causes dermatitis.
Viscum album (EUROPEAN MISTLETOE); leaves, stems; gastrointestinal tract affected by toxalbumins.
WAFER ASH (Ptelea baldwinii); plant causes photosensitization and contact dermatitis.
WAHOO (Euonymus atropurpureus); fruit; cardiovascular system affected by the glycosides evobioside, evomonoside, and evonoside.
WATER DROPWORT (Oenanthe crocata); entire plant; plant contains the convulsant oenanthetoxin.
WATER HEMLOCK (Cicuta spp.); entire plant, esp. roots; nervous system affected by the convulsant cicutoxin.
WEST INDIAN PINKROOT (Spigelia spp.); entire plant; nervous system affected by the toxin spigeline.
WHEAT (Triticum aestivum); nontoxic unless contaminated with fungi.
WHITE ANTHURIUM (Spathiphyllum spp.); entire plant; gastrointestinal tract affected by plant toxins; plant also causes dermatitis.
WHITE ARUM-LILY (Zantedeschia aethiopica); leaves; mouth irritated by plant raphides.
WHITE BRYONY (Bryonia dioica); gastrointestinal tract affected by the glycosides bryonin and bryonidin; plant also causes dermatitis.
WHITE CALLA (Zantedeschia aethiopica); leaves; mouth irritated by plant raphides.
WHITE CLOVER (Trifoliurn repens); plant is cyanogenetic.
WHITE OZIER (Leucothoe spp.); leaves, nectar; cardiovascular and nervous systems affected by plant toxins.
WHITE SNAKEROOT (Eupatorium sp.); leaves; plant may contain toxic levels of nitrates.
WHITE SWEETCLOVER (Melilotus sp.); plant may contain toxic levels of nitrates.
WHORLED BUTTERFLY (Asclepias sp.); leaves, stems; plant contains toxic resins.
WILD ARTICHOKE (Helianthus annuus); plant may contain toxic levels of nitrates.
WILD BALSAM-APPLE (Momordica charantia); seeds; gastrointestinal tract affected by toxalbumins.
WILD PARSNIP (Pastinaca sativa); plant causes dermatitis.
WILD PEA (Lathyrus spp.); stems, seeds; nervous system affected by plant toxins.
WILD SUNFLOWER (Helianthus annuus); plant may contain toxic levels of nitrates.
WINDFLOWER (Anemone spp., includes Pulsatilla); entire plant; gastrointestinal tract affected by the toxin protoanemonin; plant also causes dermatitis.
WINTERSWEET (Acokanthera spp.); seeds; cardiovascular system affected by cardiac glycosides.
Wisteria spp. (WISTERIA); entire plant; gastrointestinal tract affected by alkaloid toxins.
WITCHGRASS (Panicum capillare); plant is hepatogenic; may contain toxic levels of nitrates.
WONDER FLOWER (Ornithogalum thyrsoides); entire plant, esp. bulbs; gastrointestinal tract affected by alkaloid toxins.
WOOD LAUREL (Daphne sp.); entire plant esp. fruit and seeds; gastrointestinal tract and kidneys affected by coumarin glycosides; plant also causes dermatitis.
WOODY ASTERS (Xylorrhiza spp.); entire plant; plant may absorb toxic levels of selenium.
WORMSEED (Chenopodium ambrosioides); plant may contain toxic levels of nitrates.
Xanthium orlentale (COCKLEBUR); leaves at sprouted two-leaf stage, germinating seeds; plant contains hydroquinone; plant also causes dermatitis.
Xanthosoma spp. (BLUE TARO, CALADIUM, INDIAN KALE, MALANGA); leaves; mouth irritated by plant raphides; plant also causes dermatitis. Xylorrhiza spp. (WOODY ASTERS); entire plant; plant may absorb toxic levels of selenium.
YAUPON (Ilex vomitoria); berries; gastrointestinal tract affected by saponins.
YELLOW ALLAMANDA (Allamanda cathartica); leaves, bark, fruit, sap, seeds; plant contains catharatic toxins.
YELLOW-BE-STILL TREE (Thevetia peruviana); entire plant, esp. seeds; cardiovascular system affected by cardiac glycosides.
YELLOW JESSAMINE (Gelsemium sempervirens); flowers, leaves, roots; plant contains convulsants, including indole; plant also causes dermatitis.
YELLOW LADY SLIPPER (Cypripedium parviflorum); leaves, stems; plant causes dermatitis.
YELLOW NIGHTSHADE (Urechites lutea); leaves; cardiovascular system affected by the cardiac glycoside urechitoxin.
YELLOW OLEANDER (Thevetia peruviana); entire plant, esp. seeds; cardiovascular system affected by cardiac glycosides.
YELLOW PINE FLAX (Linum neomexicanum); entire plant; plant is cyanogenetic.
YELLOW SWEETCLOVER (Melilotus sp.); plant may contain toxic levels of nitrates.
YEWS (Taxus spp.); entire plant, except red aril; gastrointestinal tract and cardiovascular system affected by volatile oils and the alkaloids taxine, and ephedrine.
Zamia pumila (COONTIE, FALSE SAGO PALM, FLORIDA ARROWROOT); roots, trunk; gastrointestinal tract and nervous system affected by plant toxins.
Zantedeschia aethiopica (CALLA LILY, PIG LILY, WHITE ARUM LILY, WHITE CALLA); leaves; mouth irritated by plant raphides.
Zigadenus spp. (DEATH CAMAS); entire plant; cardiovascular system affected by alkaloid toxins.