If you have small children and pets at home, poisonous flowers should not be planted in the garden or as houseplants. In this article, you will find the names of some flowers that are poisonous and must never be ingested.
Did You Know?
In 1785, the English botanist William Withering published ‘An Account of the Foxglove and some of its Medical Uses‘ which revealed how the digitalin extracted from the plant’s leaves, helped subside swelling caused by dropsy or congestive heart failure.
Plants form an indispensable part of our diet. However, there are several varieties that contain toxic chemicals, which after ingestion may prove poisonous for to both humans and animals. Take the example of ‘Oleander shrubs’ which are often grown as an ornamental plants. Its blooms are enlisted as one of the most poisonous flowers in the world. Hence, it is very important for all of us to identify such toxic plants and flowers before we introduce them into our gardens or gift them to loved ones. This Gardenerdy article lists and discusses some common poisonous flowers that should be kept away from pets and humans.
List of the Most Poisonous Flowers in the World
While laying out a flower garden, you should take note of the poisonous flowers beforehand. This step is even more important if you are a pet owner. With pets, the risk is high even if you train them to not venture near your plants. Listed below are some of the most harmful flowers that may be found in gardens and native flora near you.
Note: Only the most active toxins, popular common names, and known adverse affects have been mentioned for each flower.
Angel’s Trumpet
Scientific Name
Brugmansia
Other Common Names
Charles Grimaldi, Dr. Seuss, and Frosty Pink
Toxins Present
Scopolamine, hyoscyamine, and atropine.
Adverse Effects
Paralysis, diarrhea, or fatality
Anthurium
Scientific Name
Anthurium spp.
Other Common Names
Flamingo Flower, Tailflower and Boy Flower
Toxins Present
Raphides
Adverse Effects
Edema, dysphagia, and swelling in the tongue and throat.
Atropa Belladonna
Scientific Name
Atropa belladonna
Other Common Names
Belladonna and Deadly Nightshade
Toxins Present
Atropine, hyoscyamine, and scopolamine.
Adverse Effects
Dry mouth, dilated pupils, hallucinations, unconsciousness, paralysis or fatality.
Azalea
Scientific Name
Rhododendron
Other Common Names
Rosebay and Rhododendron
Toxins Present
Grayanotoxin and arbutin glycoside.
Adverse Effects
Diarrhea, bradycardia or slow heart rate, dizziness, vomiting, and fatality may occur in 1-2 days.
Bottlebrush
Scientific Name
Grevillea
Other Common Names
Spider Flower and Toothbrush Plant
Toxins Present
Hydrogen cyanide
Adverse Effects
Contact dermatitis, hay fever, and other allergies.
Black Henbane
Scientific Name
Hyoscyamus niger
Other Common Names
Henbane and Stinking Nightshade
Toxins Present
Hyoscyamine, atropine, and scopolamine.
Adverse Effects
Hallucinations, dilated pupils, and flushed skin.
Bloodroot
Scientific Name
Sanguinaria canadensis
Other Common Names
Tetterwort, Red Puccoon Root, and Pauson
Toxins Present
Sanguinarine
Adverse Effects
Nausea, dizziness, dilated pupils, and fainting.
Butterfly Bush
Scientific Name
Buddleja davidii
Other Common Names
Butterfly Bush, Buddleia, Orange Eye, and Summer Lilac
Toxins Present
Cardiac glycosides
Adverse Effects
Bloating, weakness, stupor, spasms, breathlessness, and pupil dilation.
Bead Tree
Scientific Name
Melia azedarach
Other Common Names
China Ball Tree, Chinaberry Tree, Japanese Bead Tree, Texas Umbrella Tree, Pride-of-India, Indian lilac, Persian Lilac, Paradise Tree, and White Cedar
Toxins Present
Tetranortriterpenoids and neurotoxin.
Adverse Effects
Salivation, diarrhea, vomiting, weakness, seizures, and fatality.
Black Nightshade
Scientific Name
Solanum nigrum
Other Common Names
Popolo, Duscle, Wonder Berry, Petty Morel, Hound’s Berry, Small-fruited Black Nightshade, and Garden Nightshade
Toxins Present
Solanine, solamargine, and solasonine.
Adverse Effects
Fever, drowsiness, sweating, confusion, stomachache, vomiting, diarrhea, cardiac arrhythmias, and respiratory failure.
Butterfly Weed
Scientific Name
Asclepias tuberosa
Other Common Names
Orange Milkweed, Canada Root, Indian Posy, Indian Paintbrush, and Fluxroot
Toxins Present
Resinoid and cardiac glycoside.
Adverse Effects
Stupor, vomiting, weakness, and muscle spasm.
Calla Lily
Scientific Name
Zantedeschia aethiopica
Other Common Names
Easter Lily and Arum Lily
Toxins Present
Oxalic acid and Asparagine.
Adverse Effects
Redness of the eyes and mouth, burning in mouth and throat, vomiting, and diarrhea.
Castor Bean
Scientific Name
Ricinus communis
Other Common Names
Castor Oil Plant
Toxins Present
Ricin
Adverse Effects
Tachycardia, hypotension, nausea, diarrhea, and seizures.
Christmas Rose
Scientific Name
Helleborus niger
Other Common Names
Hellebores and Lenten Rose
Toxins Present
Protoanemonin, glycosides, and bufadienolides.
Adverse Effects
Ulcers, vomiting blood, slow heart rate, breathlessness, cardiac arrest, or fatality.
Clematis
Scientific Name
Clematis spp.
Other Common Names
Traveller’s joy, Old Man’s Beard, Leather Flower, Vase Vine, and Virgin’s Bower
Toxins Present
Protoanemonin
Adverse Effects
Skin allergies, burning sensation in mouth, vomiting, and diarrhea.
Common Milkweed
Scientific Name
Asclepias syriaca
Other Common Names
Butterfly Flower, Silky Swallow-wort, Silkweed, and Virginia Silkweed
Toxins Present
Cardiac Glycosides
Adverse Effects
Dermatitis
Corn Lily
Scientific Name
Veratrum californicum
Other Common Names
California False Hellebore, White False Hellebore, and California Corn Lily
Toxins Present
Cyclopamine and Veratrine.
Adverse Effects
Hypotension, slowed heart rate, spasms, vomiting, paralysis, and convulsions.
Dumb Cane
Scientific Name
Dieffenbachia
Other Common Names
Mother-in-law Plant
Toxins Present
Raphides
Adverse Effects
Burning and swelling in mouth and throat, erythema, and salivation.
Euphorbia
Scientific Name
Euphorbia
Other Common Names
Spurges, Akoko, and Tabaibas
Toxins Present
Terpene Esters and Caustic Lattices.
Adverse Effects
Inflammation of the skin, eyes, and mucous membrane.
False Indigo
Scientific Name
Baptisia australis
Other Common Names
Blue Wild Indigo, Blue False Indigo, Indigo, Horsefly Weed, or Rattlebush
Toxins Present
Baptisin and Cytisine.
Adverse Effects
Vomiting and diarrhea.
Foxglove
Scientific Name
Digitalis
Other Common Names
Lady’s Glove
Toxins Present
Digitoxin and Digoxin.
Adverse Effects
Lowered pulse rate, vomiting, spasms, breathlessness, contact dermatitis, cardiac arrest or fatality.
Frangipani
Scientific Name
Plumeria
Other Common Names
Temple Tree
Toxins Present
Terpene Esters and Caustic Lattices.
Adverse Effects
Contact dermatitis, burning in eyes and mouth, nausea, and vomiting.
Four O’Clock
Scientific Name
Mirabilis jalapa
Other Common Names
Marvel of Peru
Toxins Present
Trigonelline
Adverse Effects
Skin irritation, stomachache, nausea, vomiting, diarrhea, and hallucinations.
False Acacia
Scientific Name
Robinia pseudoacacia
Other Common Names
Black locust
Toxins Present
Toxalbumin robin (Although the flowers are poisonous, they can be eaten after being dipped in batter and fried in oil.)
Adverse Effects
Dizziness, drowsiness, nausea, vomiting, convulsions, and diarrhea.
Gloriosa Lily
Scientific Name
Gloriosa superba
Other Common Names
Glory Lily, Flame Lily, and Fire Lily
Toxins Present
Colchicine
Adverse Effects
Burning and tingling in mouth, nausea, vomiting, hypotension, seizures, or fatality.
Golden Chain
Scientific Name
Laburnum
Other Common Names
Alpine laburnum and Common Laburnum
Toxins Present
Cytisine
Adverse Effects
Hypertension, nausea, vomiting, dizziness, convulsions, coma, or fatality.
Heavenly Bamboo
Scientific Name
Nandina domestica
Other Common Names
Nandina and Sacred Bamboo
Toxins Present
Hydrocyanic acid and Nantenine.
Adverse Effects
Weakness, breathlessness, incoordination, seizures, coma, or fatality.
Horse Chestnut
Scientific Name
Aesculus hippocastanum
Other Common Names
Conker Tree
Toxins Present
Esculin, Saponin and Glycoside.
Adverse Effects
Nausea, contact dermatitis, itching, and stomach ulcers.
Hyacinth
Scientific Name
Hyacinthus
Other Common Names
Garden Hyacinth, Common Hyacinth, and Dutch Hyacinth
Toxins Present
Oxalic acid
Adverse Effects
Contact dermatitis and gastrointestinal irritation such as colic, diarrhea, and vomiting.
Hyacinth Bean
Scientific Name
Lablab purpureus
Other Common Names
Dolichos Bean, Egyptian Kidney Bean, Seim Bean, Indian Bean, Australian Pea, and Lablab Bean
Toxins Present
Cyanogenic glycosides
Adverse Effects
Both flowers and beans are edible but mildly toxic, and must be steamed or cooked before consumption.
Hydrangea
Scientific Name
Hydrangea spp.
Other Common Names
Hortensia
Toxins Present
Cyanogenic glycoside
Adverse Effects
Nausea, vomiting, weakness, breathlessness, and diarrhea.
Iris
Scientific Name
Iris spp.
Other Common Names
Flags and Junos
Toxins Present
Iridin
Adverse Effects
Burning sensation in mouth. The flowers are mildly toxic as compared to their highly poisonous root bulbs.
Ivy
Scientific Name
Hedera spp.
Other Common Names
Sweetheart Ivy, Branching Ivy, California Ivy, and Needlepoint Ivy
Toxins Present
Hederagenin
Adverse Effects
Vomiting, headache, stomachache, diarrhea and excess salivation.
Laceflower
Scientific Name
Ammi majus
Other Common Names
Bishop’s Weed/Flower, Bullwort, Lady’s Lace, Greater Ammi, and False Queen Anne’s Lace
Toxins Present
Nitrates and Furanocoumarins.
Adverse Effects
Nausea, headache, vertigo, allergies, lack of appetite, constipation, and sleeplessness.
Lantana
Scientific Name
Lantana spp.
Other Common Names
Shrub verbenas
Toxins Present
Lantadene A and B
Adverse Effects
Toxic for the liver, photosensitivity, drowsiness, and vomiting. This plant can kills pets and grazing animals.
Larkspur
Scientific Name
Delphinium spp.
Other Common Names
Lark’s Claw, Knight’s Spur, and Lark’s Heel
Toxins Present
Alkaloid delphinine
Adverse Effects
Contact dermatitis, burning of mouth, vomiting, spasms, depression, breathlessness, and convulsion. Fatal for pets and grazing animals.
Leopard’s Bane
Scientific Name
Arnica montana
Other Common Names
Wolf’s Bane, Mountain Arnica, and Mountain Tobacco
Toxins Present
Helenalin
Adverse Effects
Vomiting, drowsiness, shortness of breath, and heart palpitation.
Lilium
Scientific Name
Lilium spp.
Other Common Names
Lily
Toxins Present
Calcium oxalate
Adverse Effects
Burning sensation in mouth and throat. Fatal for cats.
Lily of the Valley
Scientific Name
Convallaria majalis
Other Common Names
May Lily, Muguet, and May Bells
Toxins Present
Azetidine-2-carboxylic acid, saponins, and 38 cardiac glycosides.
Adverse Effects
Stomachache, nausea, vomiting, and lowered heart rate.
Lords and Ladies
Scientific Name
Arum maculatum
Other Common Names
Adder’s root, Wild Arum, Arum Lily, Snakeshead, and Devils and Angels
Toxins Present
The berries are in fact the plant’s female flowers. These berries contain toxic saponin oxalates.
Adverse Effects
Skin, mouth, tongue, and throat irritation, swelling of throat, burning pain, breathlessness, and stomach upset.
Lobelia
Scientific Name
Lobelia spp.
Other Common Names
Cardinal Flower, Indian Tobacco, and Indian Pink
Toxins Present
Lobeline and lobelamine.
Adverse Effects
Poisonous for pets and toxic for humans. Symptoms include, salivation, weakness, nausea, vomiting, diarrhea, dilated pupils, euphoria, or convulsions.
Marsh Marigold
Scientific Name
Caltha palustris
Other Common Names
Mollyblobs, Mayflower, May blobs, and Kingcup
Toxins Present
Protoanemonin and glycoside
Adverse Effects
Salivation, irritation in the mouth, throat, diarrhea, and hemoglobinuria.
Meadow Saffron
Scientific Name
Colchicum autumnale
Other Common Names
Meadow saffron, Autumn Crocus, and Naked Lady
Toxins Present
Colchicine
Adverse Effects
Burning sensation in mouth, throat, and stomach, bloating and gas.
Monkshood
Scientific Name
Aconitum napellus
Other Common Names
The Queen of Poisons, Wolf’s Bane, Devil’s Helmet, Aconite, Women’s Bane, and Blue Rocket
Toxins Present
Aconitine and diterpene alkaloids.
Adverse Effects
Excessive salivation, breathlessness, nausea, vomiting, burning sensation in mouth and stomach, diarrhea, tingling and numbness in mouth and face, seizures, coma, or fatality.
Moonflower
Scientific Name
Datura spp.
Other Common Names
Datura, Downy Thornapple, and Jimson weed
Toxins Present
Atropine, hyoscyamine, and scopolamine.
Adverse Effects
Delirium, hyperthermia, dilated pupils, amnesia, seizures, coma, or fatality.
Morning Glory
Scientific Name
Ipomoea spp.
Other Common Names
Sweet Potato, Moonflower, and Bindweed
Toxins Present
Indole alkaloids such as chanoclavine, elymoclavine, lysergic acid, and lysergamide.
Adverse Effects
Disorientation, agitation, gastrointestinal upset, tremors, ataxia, hallucination, or delirium.
Mandrake
Scientific Name
Mandragora spp.
Other Common Names
Satan’s Apple
Toxins Present
Atropine, apoatropine, hyoscyamine, and scopolamine.
Adverse Effects
Anticholinergic, narcotic, purgative, hypnotic, emetic, and hallucinogen.
Mountain Laurel
Scientific Name
Kalmia latifolia
Other Common Names
Calico-bush and Spoonwood
Toxins Present
Grayanotoxin and arbutin
Adverse Effects
Neurotoxic symptoms, gastrointestinal problems, difficulty breathing, excessive salivation, repeated swallowing, weakness, eyes and nose watering, depression, vomiting, frequent defecation, anorexia, convulsions, loss of motor control, paralysis, coma, and fatality.
Narcissus
Scientific Name
Narcissus spp.
Other Common Names
Daffodil, Jonquil, and Paperwhite Daffodil
Toxins Present
Lycorine
Adverse Effects
Dermatitis, vomiting, diarrhea, low blood pressure, or cardiac arrhythmia.
Nicotiana
Scientific Name
Nicotiana spp.
Other Common Names
Flowering Tobacco, Jasmine Tobacco, and Woodland Tobacco
Toxins Present
Nicotine
Adverse Effects
Nausea, vomiting, dizziness, and headache.
Oleander
Scientific Name
Nerium Oleander
Other Common Names
Rose Bay, Rose Laurel, Adelfa, Laurel Rosa, and Karvira
Toxins Present
Cardiac glycosides: Oleandrin and oleandrigenin.
Adverse Effects
Excess salivation, vomiting, gastric upset, drowsiness, irregular heartbeat, seizures, coma, or death.
Pheasant’s Eye
Scientific Name
Adonis vernalis
Other Common Names
False Hellebore, Yellow Pheasant’s Eye, and Spring Pheasant’s Eye
Toxins Present
Toxic cardiac glycosides
Adverse Effects
Vomiting, diarrhea, lower pulse, irregular heartbeat, and unconsciousness.
Periwinkle
Scientific Name
Vinca spp.
Other Common Names
Running Myrtle
Toxins Present
Vinca Alkaloids
Adverse Effects
Low blood pressure, vomiting, diarrhea, depression, tremors. Can prove fatal for small pets.
Poison Hemlock
Scientific Name
Conium maculatum and C. chaerophylloides
Other Common Names
Hemlock, Beaver Poison, Herb Bennet, Devil’s Bread, Devil’s Porridge, Musquash Root, Spotted Hemlock, and Poison Parsley
Toxins Present
Coniine, conhydrine, gamma-coniceine, N-methylconiine, pseudoconhydrine.
Adverse Effects
Poisonous to animals and humans. Burning in the mouth, salivation, diarrhea, tremors, muscle spasms, blurry vision, coma, respiratory failure, coma, or death.
Pokeroot
Scientific Name
Phytolacca spp.
Other Common Names
Inkberry, Pokeberry, Pokeweed, Pokebush, and Poke Sallet
Toxins Present
Tocix saponin
Adverse Effects
Dizziness, burning in mouth and throat, nausea, vomiting, diarrhea, weakness, rapid heartbeat, and unconsciousness.
Poppy
Scientific Name
Papaver nudicaule and other species
Other Common Names
—-
Toxins Present
Chelidonine, amurine, amurensine, amurensinine, flavinantine, and O-methylthalisopavine.
Adverse Effects
Nausea, vomiting, stomachache and bloating, muscle spasm, and twitching. May cause restlessness in humans as well as livestock.
Potato Flower
Scientific Name
Solanum tuberosum
Other Common Names
White Potato, Potato, Common Potato, Irish Potato, and European Potato
Toxins Present
Solanine
Adverse Effects
Headache, vomiting, dilated pupils, delirium, numbness, confusion, diarrhea, salivation, sleepiness, and weakness.
Ranunculus
Scientific Name
Ranunculus spp.
Other Common Names
Butter Cress and Figwort
Toxins Present
Protoanemonin
Adverse Effects
Salivation, diarrhea, stomachache, and blisters in mouth, contact dermatitis.
Rhododendron
Scientific Name
Rhododendron spp.
Other Common Names
—-
Toxins Present
Grayanotoxin and arbutin glucoside.
Adverse Effects
Salivation, nausea, vomiting, dizziness, weakness, breathing problems, and loss of balance.
Scotch Broom
Scientific Name
Cytisus scoparius
Other Common Names
Common Broom, Scot’s Broom, and English Broom
Toxins Present
Tyramine, spiraeoside, scoparoside, quinolizidine, and sparteine.
Adverse Effects
Rapid heart rate, vomiting, stomachache, and incoordination.
Sweet Pea
Scientific Name
Lathyrus odoratus
Other Common Names
Everlasting Pea, Perennial Peavine, and Perennial Pea
Toxins Present
Beta-aminopropionitrile and lathyrogens.
Adverse Effects
Difficulty in breathing, convulsions, and paralysis.
Sky Flower
Scientific Name
Duranta Erecta
Other Common Names
Golden Dewdrop, Pigeon Berry, and Duranta Repens
Toxins Present
Saponins
Adverse Effects
Vomiting, fever, gastric problems, drowsiness, or fatality.
White Snakeroot
Scientific Name
Ageratina altissima
Other Common Names
White Sanicle, Richweed, and Tall Boneset
Toxins Present
Tremetol
Adverse Effects
Listlessness, convulsions, coma, and fatality.
Star-of-Bethlehem
Scientific Name
Ornithogalum spp.
Other Common Names
Chincherinchee
Toxins Present
Cardiac glycoside and ornithogalum.
Adverse Effects
Abnormal heart rhythm, dilated pupils, nausea, excess salivation, vomiting, stomachache, tremor, and seizure.
Tree Philodendron
Scientific Name
Philodendron bipinnatifidum
Other Common Names
Lacy Tree Philodendron and Selloum
Toxins Present
Calcium oxalate
Adverse Effects
Irritation and swelling in mouth and throat, diarrhea, and vomiting. May prove fatal for cats and rats.
Wisteria
Scientific Name
Wisteria spp.
Other Common Names
—-
Toxins Present
Toxic lectins
Adverse Effects
Headache, gastroenteritis, dizziness, confusion, and hematemesis.
Wood Anemone
Scientific Name
Anemone nemorosa
Other Common Names
Thimbleweed, Smell Fox, and Windflower
Toxins Present
Protoanemonin
Adverse Effects
Gastrointestinal and skin irritation, burning and ulcers in mouth and throat, nausea, vomiting, hematemesis, and diarrhea.
Yellow Oleander
Scientific Name
Thevetia peruviana
Other Common Names
Lucky Nut
Toxins Present
Oleandrin, Oleondroside, Thevetin A, Thevetin B, neriifolin, peruvoside, ruvoside, thevetoxin, etc.
Adverse Effects
Excess salivation, vomiting, gastric upset, drowsiness, irregular heartbeat, seizures, coma, or death.
Cherry Laurel
Scientific Name
Prunus caroliniana and Prunus laurocerasus
Other Common Names
Laurel, Carolina Cherry Laurel, and English Laurel
Toxins Present
Cyanogenic glycosides and amygdalin.
Adverse Effects
Gasping, weakness, dilated pupils, spasms, convulsions, respiratory failure, or coma.
Greater Celandine
Scientific Name
Chelidonium majus
Other Common Names
European Tetterwort, Yellow Spit, Wartwort, St John’s Wort, and Jacob’s Ladder
Toxins Present
The latex contains toxic chelidonine. Isoquinoline alkaloids are present in the roots.
Adverse Effects
Acute hepatitis, contact dermatitis, blisters, burning and ulcers in mouth and throat, vomiting, and nerve paralysis.
Privet
Scientific Name
Ligustrum vulgare
Other Common Names
Common Privet, Wild Privet, and European Privet
Toxins Present
Syringin and shikimic acid.
Adverse Effects
Asthma, eczema, weakness, headache, low blood pressure, nausea, vomiting, stomach pain, diarrhea, and lowered body temperature.
Rain Lily
Scientific Name
Zephyranthes spp.
Other Common Names
Zephyr Lily, Fairy Lily, Magic Lily, Rainflower, and Atamasco Lily
Toxins Present
Calcium oxalate, haemanthamine and lycorine.
Adverse Effects
Irritation on skin, and swelling, burning, and pain in the mouth, tongue, and throat. Breathlessness, vomiting, upset stomach, convulsions, or fatality.
Schefflera
Scientific Name
Schefflera arboricola
Other Common Names
Dwarf Umbrella Tree
Toxins Present
Calcium oxalate (Toxic to dogs and cats as well)
Adverse Effects
Upset stomach and pain, breathlessness, salivation, and renal problems.
Yesterday, Today, and Tomorrow
Scientific Name
Brunfelsia pauciflora
Other Common Names
Morning-noon-and-night, Brazil Raintree, Brunfelsia, Lady-of-the-night plant, and Kiss-Me-Quick
Toxins Present
Brunfelsamidine and hopeanine.
Adverse Effects
Excessive salivation, vomiting, diarrhea, tremor, delirium, hallucinations, and seizure. May prove fatal for pets.
If you have pets at home, you should avoid planting the aforementioned flowers in the vicinity of the house. The best way is to consult a horticulturist and seek advice regarding flowers that are harmful for dogs, cats, and other pets.