Poisonous Flowers: 60+ Toxic Blooms to Keep Away from Pets & Children

Gardens delight the senses, but some beautiful flowers harbor dangerous toxins. If you have curious children, dogs, cats, or livestock, knowing which plants are poisonous—and how toxic they are—is essential for safety. This guide covers 60+ common garden and houseplant flowers with their toxins, effects, and risk levels.

Why Flowers Produce Toxins

Chemical defenses (alkaloids, glycosides, terpenes, etc.) deter herbivores. While many plants are mildly irritating, some contain compounds that can cause severe illness or death even in small amounts. Toxicity varies by plant part, dose, and species sensitivity (e.g., lilies are fatal to cats but less so to dogs).

High-Risk Flowers (Severe Toxicity / Fatal Potential)

Flower	Scientific Name	Key Toxins	Primary Risks
Angel's Trumpet	Brugmansia	Scopolamine, hyoscyamine, atropine	Paralysis, hallucinations, death
Atropa Belladonna (Deadly Nightshade)	Atropa belladonna	Atropine, hyoscyamine, scopolamine	Hallucinations, paralysis, death
Oleander	Nerium oleander	Oleandrin, oleandrigenin (cardiac glycosides)	Irregular heartbeat, seizures, death
Yellow Oleander	Thevetia peruviana	Similar cardiac glycosides	Same as oleander
Castor Bean	Ricinus communis	Ricin	Organ failure, death (seeds most toxic)
Monkshood / Wolfsbane	Aconitum napellus	Aconitine, diterpene alkaloids	Numbness, paralysis, heart failure, death
Foxglove	Digitalis purpurea	Digitoxin, digoxin	Cardiac arrest, death (source of heart drug)
Lily of the Valley	Convallaria majalis	38 cardiac glycosides	Low heart rate, vomiting, death
Rhododendron / Azalea	Rhododendron	Grayanotoxin	Vomiting, weakness, coma, death
Mountain Laurel	Kalmia latifolia	Grayanotoxin, arbutin	Severe neurotoxicity, death
Yew	Taxus baccata	Taxine alkaloids	Sudden cardiac death
Autumn Crocus / Meadow Saffron	Colchicum autumnale	Colchicine	Multi-organ failure, death
Gloriosa Lily	Gloriosa superba	Colchicine	Severe GI, hypotension, death
Datura / Moonflower / Jimsonweed	Datura spp.	Atropine, hyoscyamine, scopolamine	Delirium, hyperthermia, death
White Snakeroot	Ageratina altissima	Tremetol	Tremors, coma, death (milk sickness)
Poison Hemlock	Conium maculatum	Coniine, related alkaloids	Respiratory paralysis, death

Moderate-Risk Flowers (Significant Illness Likely)

• Anthurium / Flamingo Flower – Calcium oxalate raphides; severe mouth/throat swelling, dysphagia.
• Calla Lily – Oxalic acid, asparagine; burning, vomiting, diarrhea.
• Dumb Cane (Dieffenbachia) – Raphides; intense oral pain, swelling.
• Hyacinth – Oxalic acid; contact dermatitis, GI upset.
• Hydrangea – Cyanogenic glycosides; nausea, vomiting, weakness.
• Iris – Iridin; mouth burning (roots more toxic).
• Larkspur / Delphinium – Alkaloid delphinine; neuromuscular paralysis, fatal to pets.
• Lantana – Lantadenes; liver damage, photosensitivity; kills grazing animals.
• Morning Glory (Ipomoea) – Indole alkaloids (LSA); hallucinations, GI upset.
• Narcissus / Daffodil – Lycorine; vomiting, diarrhea, cardiac arrhythmia (bulbs most toxic).
• Nicotiana / Flowering Tobacco – Nicotine; nausea, vomiting, dizziness.
• Ranunculus / Buttercup – Protoanemonin; blisters, salivation, dermatitis.
• Sweet Pea – Beta-aminopropionitrile; lathyrism (paralysis, convulsions).
• Wisteria – Lectins; gastroenteritis, hematemesis.
• Cherry Laurel – Cyanogenic glycosides; respiratory failure, coma.
• Rain Lily (Zephyranthes) – Calcium oxalate, lycorine; oral irritation, convulsions.
• Schefflera – Calcium oxalate; renal issues in pets.
• Yesterday-Today-Tomorrow (Brunfelsia) – Brunfelsamidine; seizures, fatal to pets.

Lower-Risk / Irritant Flowers

• Bottlebrush (Grevillea) – Hydrogen cyanide; contact dermatitis, hay fever.
• Black Henbane – Tropane alkaloids; hallucinations (rarely fatal).
• Bloodroot – Sanguinarine; nausea, fainting.
• Butterfly Bush – Cardiac glycosides; bloating, weakness.
• Bead Tree (Melia azedarach) – Neurotoxins; seizures, fatal in large doses.
• Black Nightshade – Solanine; GI, cardiac, respiratory effects.
• Butterfly Weed (Asclepias tuberosa) – Cardiac glycosides; stupor, vomiting.
• Christmas Rose (Helleborus niger) – Protoanemonin, bufadienolides; cardiac arrest.
• Clematis – Protoanemonin; skin allergies, GI upset.
• Corn Lily (Veratrum) – Cyclopamine, veratrine; hypotension, convulsions.
• Euphorbia / Spurge – Terpene esters; skin/eye/mucous membrane inflammation.
• False Indigo (Baptisia) – Baptisin, cytisine; vomiting, diarrhea.
• Frangipani (Plumeria) – Terpene esters; dermatitis, nausea.
• Four O'Clock (Mirabilis jalapa) – Trigonelline; GI upset, hallucinations.
• False Acacia (Robinia) – Toxalbumin; flowers edible if battered/fried.
• Golden Chain (Laburnum) – Cytisine; hypertension, convulsions, coma.
• Heavenly Bamboo (Nandina) – Hydrocyanic acid; seizures, coma.
• Horse Chestnut – Esculin, saponin; nausea, dermatitis.
• Hyacinth Bean – Cyanogenic glycosides; edible if cooked.
• Leopard's Bane (Arnica) – Helenalin; vomiting, heart palpitations.
• Lilium (True Lilies) – Calcium oxalate; fatal to cats.
• Lords & Ladies (Arum maculatum) – Saponin oxalates; throat swelling.
• Lobelia – Lobeline; salivation, convulsions.
• Marsh Marigold – Protoanemonin; salivation, hemoglobinuria.
• Mandrake – Tropane alkaloids; hallucinogenic, purgative.
• Pheasant's Eye (Adonis) – Cardiac glycosides; arrhythmia, unconsciousness.
• Periwinkle (Vinca) – Vinca alkaloids; hypotension, tremors.
• Pokeroot (Phytolacca) – Saponins; burning, rapid heartbeat.
• Poppy (Papaver) – Multiple alkaloids; GI, muscle spasms.
• Potato Flower – Solanine; neurotoxic.
• Scotch Broom (Cytisus) – Quinolizidine alkaloids; incoordination.
• Sky Flower (Duranta) – Saponins; GI, fatality possible.
• Star-of-Bethlehem (Ornithogalum) – Cardiac glycosides; arrhythmia, seizures.
• Tree Philodendron – Calcium oxalate; fatal to cats/rats.
• Wood Anemone – Protoanemonin; GI, skin irritation.
• Greater Celandine – Chelidonine, isoquinoline alkaloids; hepatitis, nerve paralysis.
• Privet (Ligustrum) – Syringin, shikimic acid; asthma, hypotension.

Safety Guidelines

• Identify before you plant: Research every new plant's toxicity.
• Teach children: "Never eat plants without asking an adult."
• Pet-proof: Fence off toxic beds; use hanging baskets for indoor toxins.
• Know your vet's number and ASPCA Animal Poison Control: (888) 426-4435.
• Save plant tags or take photos for quick ID if ingestion occurs.
• Consider non-toxic alternatives: Zinnias, marigolds, snapdragons, sunflowers, petunias, roses (thorns aside), herbs.

Beauty and danger often grow side by side. With knowledge and precautions, you can enjoy a stunning garden while keeping your loved ones—two-legged and four-legged—safe.