Aconite, Monkshood
Aconitum
All parts can be fatal if ingested

African Milk Bush
Synadenium
All parts can be fatal if ingested

Almond
Prunus amygdalus
Leaves and fruit can cause severe digestive upset and respiratory distress

Aloe
Aloe vera
Toxic if ingested

Amaryllis
Hippeastrum
Can cause severe digestive upset and neurological damage

Angel’s Trumpet
Brugmansia
Extremely toxic -- all parts can be fatal if ingested

Apple
Malus sylvestris
Seeds contain cyanide and can be toxic if chewed and ingested in large quantities

Arnica
Arnica
All parts can cause severe discomfort

Autumn Crocus
Colchicum
Extremely toxic -- all parts can be fatal if ingested

Avocado
Persea americana
Pits, fruit and plants can cause respiratory distress and congestive heart failure

Azalea
Rhododendron
Can cause stomach irritation, abdominal pain, abnormal heart rate and rhythm, convulsions, coma and neurological damage

Baneberry
Actaea rubra
Berries are highly toxic

Begonia
Begoniaceae
Can cause kidney and organ failure

Bird of Paradise
Strelitzia regenia
Can cause severe digestive upset

Black Locust, Globe
Robinia
Can cause severe digestive upset

Bleeding Heart
Dicentra spectabilis
Toxic to cardiovascular system

Bloodroot
Sanguinaria
Can cause severe digestive upset

Bluebell
Hyacinthoides
Can cause severe digestive upset

Bouncing Bet
Saponaria
Can cause severe digestive upset

Boxwood
Buxus
Can cause severe digestive upset

Bracken Fern
Pteridium esculentum
Can cause neurological damage

Broom
Cytisus
Can cause severe digestive upset

Buckeye, Chestnut
Aesculus
Can cause severe digestive upset and neurological damage

Buckthorn
Rhamnus
Can cause severe digestive upset

Bushman’s Poison
Acokanthera
Sap and fruits are highly toxic

Buttercup
Rununcula
Can cause severe digestive upset

Buttonbush
Cephalanthus
Can cause severe discomfort

Caladium
Caladium hortulanum
Can cause kidney and organ failure

Calla Lily
Zantedeschia
All parts cause stomach upset and kidney and/or organ failure

Castor Bean
Ricinus communis
Highly toxic, can cause nausea, abdominal pain, bloody diarrhea, tenesmus, dehydration, shortness of breath, excessive thirst, weakness, muscle twitching, convulsions, coma and death

Chokecherry
Prunus virginiana
Can cause severe digestive upset and respiratory distress

Chrysanthemum
Leucanthemum
Can cause severe digestive upset and neurological damage

Clematis
Clematis spp.
Can cause severe digestive upset

Comfrey
Symphytum
Leaves and roots cause severe digestive upset

Coriaria
Coriaria
Seeds toxic; fruits of some species edible, but others cause severe stomach upset

Corn Cockle
Agrostemma
Seeds can cause severe discomfort

Cow Parsnip
Heracleum
Can cause severe digestive upset

Creeping Charlie
Glechoma hederacea
All parts can cause upset stomach and drooling

Crocus
Crocus
Can cause severe digestive upset and neurological damage

Croton
Codiaeum
Can cause severe digestive upset

Cyclamen
Cyclamen
Can cause severe digestive upset

Daffodil
Narcissus
Can cause severe digestive upset, tremors, seizures

Daphne
Daphne
All parts can be fatal if ingested

Death Camas
Zigadenus
All parts can be fatal if ingested

Desert Rose
Adenium
Sap causes intestinal discomfort and skin irritation

Dogbane
Apocynum
Rhizome can be fatal if eaten

Dogwood
Cornus
Fruits of some species can cause upset stomach

Dorstenia
Dorstenia
All parts can be fatal if ingested

Corn Plant
Dracaena
Can cause severe digestive upset

Drooping Leucothoe
Leucothoe fontanesiana
All parts can cause upset stomach

Dumb Cane
Dieffenbachia
Can cause severe digestive upset and respiratory distress

Easter Cactus
Schlumbergera bridgesii
Can cause severe digestive upset

Easter Lily
Lilium longiflorum
Can cause severe digestive upset

Elderberry
Sambucus
Can cause severe digestive upset and respiratory distress

Elephant’s Ear
Colocasia
All parts can cause stomach upset

English Ivy
Hedera
Can cause severe digestive upset, diarrhea, troubled breathing, coma and death

Devil’s Ivy
Epipremnum
Can cause severe digestive upset

Ferns
Most species
Can cause severe digestive upset

Fire Lily
Gloriosa
All parts can be fatal if ingested

Flamingo Flower
Anthurium
All parts can cause stomach upset and kidney and/or organ failure

Flax
Limun
Can cause stomach upset

Foxglove
Digitalis
All parts can be fatal if ingested

Golden Chain Tree
Laburnum
All parts can be fatal if ingested

Pothos
Scindapsus aureus
Can cause severe digestive upset

Golden Trumpet
Allamanda
All parts can cause stomach upset

Heavenly Bamboo
Nandina
Toxic to the respiratory system

Hellebore
Helleborus
Can cause severe digestive upset

Hemlock
Tsuga
Can cause dilated pupils, frothing at the mouth, muscle spasms, restlessness, convulsions and death within 15 minites to two hours

Horsetail
Equisetum
Can cause severe digestive upset

Hyacinth
Hyacinthus
Can cause severe digestive upset and tremors, colic, vomiting and diarrhea

Hydrangea
Hydrangea
Irritation and inflammation of the digestive tract, diarrhea, bloody stool, respiratory distress

Iris
Iris
Can cause severe digestive upset

Jack-in-the-Pulpit
Arisaema triphyllum
Can cause kidney and organ failure

Japanese Anise Tree
Illicium anisatum
Seeds are toxic and may kill if eaten in large quantities

Japanese Show Lily
Lilium speciosum
Can cause severe digestive upset

Jasmine / Jessamine
Jasminium
All parts can cause upset stomach

Jimson Weed
Datura stramonium
Can cause rapid pulse, respiratory distress, dilated pupils, restlessness, nervousness, twitching, frequent urination, diarrhea, depression, weight loss, weak pulse, convulsions, coma and death

Johnsongrass
Sorghum halepense
Can cause breathing problems, severe anxiety, convulsions, coma and death

Joint Fir, Mormon Tree
Ephedra
Can be toxic if ingested

Juniper
Juniperus
Berries can cause kidney failure

Kaffir Lily Flower
Clivia miniata
All parts can upset stomach

Kalanchoe
Kalanchoe
Toxic to cardiovascular system

Kalmia
Kalmia
Can cause severe digestive upset

Lantana
Shrub verbena
Can cause severe digestive upset, sluggishness, weakness, bloody diarrhea, kidney and/or organ failure and death

Larkspur, Delphinium
Consolida
Can cause severe digestive upset and neurological damage

Lily-of-the-Valley
Convallaria
Seeds can upset stomach

Lily-of-the-Valley Bush, Japanese Andromeda
Pieris japonica
Seeds can upset stomach

Lords-and-Ladies
Arum
Can cause severe intestinal discomfort

Lupine
Lupinus
Seeds cause severe digestive upset and neurological damage

Marsh Marigold
Caltha
Can cause severe intestinal discomfort

Mayapple
Podophyllum
All parts except fully ripe fruit are highly toxic and deadly

Milkweed
Euphorbia
Can cause severe digestive upset

Mistletoe
Viscum album
Toxic to cardiovascular system and can cause neurological damage

Moonseed
Menispermum
Fruits cause severe digestive upset

Morning Glory
Ipomoea
Seeds are highly toxic and can be fatal if ingeseted

Mountain Laurel
Kalmia latifolia
Toxic to cardiovascular system

Nephthytis
Syngonium
All parts cause stomach upset

Nightshade
Solanum
Can cause hallucinations, diarrhea, drowsiness, numbness, trembling, respiratory and cardiovascular distress, paralysis, bloat and death

Oak
Quercus
Acorns can cause severe stomach upset and organ failure

Oats
Avena sativa
Can cause respiratory distress, paralysis, convulsions and death

Oleander
Nerium
All parts can be fatal if ingested

Orange Daylily
Hemerocallis fulva
Can cause severe digestive upset

Oxford Ragwort
Senecio
Can cause severe digestive upset

Peace Lily
Spathiphyllum
All parts cause stomach upset and mouth ulcers

Peach
Prunus persica
Leaves can cause severe digestive upset and respiratory distress

Pencil Cactus
Euphorbia tirucalli
Can cause severe digestive upset

Peony
Paeonia
Toxic if ingested

Petteria
Petteria
Fruit and sap can cause severe digestive upset

Philodendron
Philodendron
Can cause severe digestive upset and kidney and/or organ failure

Pigweed, Redroot
Amaranthus retroflexus
Can cause respiratory distress, trembling, coma and death

Plum
Prunus
Leaves can cause severe digestive upset and respiratory distress

Poinsettia
Euphorbia pulcherrima
Can cause skin, mouth, eye and stomach irritation and neurological damage; not fatal

Pokeweed, Inkberry
Phytolacca
Can cause severe digestive upset, colic, diarrhea, bloody stool, anemia and death

Potato Plant
Solanum tuberosum
Leaves and stems can cause neurological damage

Precatory Bean,
Rosary Pea
Arbus precatorius
All parts can be fatal if ingested

Prickly Poppy
Argemone
Seeds can cause severe discomfort

Privet
Ligustrum
Can cause severe digestive upset

Red Lily, Pine Lily
Lilium catesbaei
Can cause severe digestive upset

Rhododendron
Rhododendron
Can cause stomach irritation, abdominal pain, abnormal heart rate and arrythmia, convulsions, coma and neurological damage

Rhubarb
Rheum
Leaves can cause severe digestive upset, staggering, trembling, respiratory distress, kidney and organ failure, weakness, diarrhea, increased urination and death

River Lily, Veld Lily
Crinum
Can cause severe digestive upset

Rubrum Lily
Lilium speciosum
Can cause severe digestive upset

Rue
Ruta
Can cause severe digestive upset

Schefflera
Schefflera
Can cause kidney and organ failure

Scopolia
Scopolia
All parts can be fatal if ingested

Shamrock
Oxalis
Can cause kidney and organ failure

Stargazer Lily
Lilium
Can cause severe digestive upset

Star-of-Bethlehem
Campanula isophylla
Can cause severe digestive upset

Sumac
Rhus
All parts can be fatal if ingested

Thevetia
Thevetia
All parts can be fatal if ingested

Tiger Lily
Lilium lancifolium
Can cause severe digestive upset

Tobacco
Nicotiana
All parts can cause upset stomach

Tomato
Lycopersicon esculentum
All parts except fruit can cause severe digestive upset and neurological damage

Trumpet Vine
Campsis radicans
All parts can be fatal if ingested

Tuberose
Polianthes tuberosa
Can cause kidney and organ failure

Tulip
Tulipa
Can cause severe digestive upset

Tung Oil Tree
Aleurites
Can cause discomfort if eaten

Tylecodon
Tylecodon
Highly toxic and fatal if eaten

Veratrum
Veratrum
All parts can be fatal if ingested

Virginia Creeper Vine
Parthenocissus quinquefolia
Can cause severe digestive upset, headache and kidney damage

Water Dropwort
Oenanthe
Can cause severe digestive upset; some species are highly toxic

Wisteria
Wisteria
Can cause severe digestive upset

Wood Lily
Prairie Trillium
Trillium vaseyi
Can cause severe digestive upset (other common names include Bloody Butcher, Purple Wakerobin and Trinity Flower)

Yew
Taxus
Can cause stomach upset respiratory and cardiovascular distress, trembling, weakness and very sudden death