Ken Tuckwell      
      Laurel Mikelson      
      Drew Kutschenreuter      

Toxic Substances     House Plants     Holiday Plants     Links     References

  In the USA, whereas overdoses of iron supplements is the most prevalent cause of pediatric adverse reactions reported to Poison Control Centers, due to children's tendency to explore their world through taste testing and putting items in their mouths, inquires relating to house plant toxicity are the most common child-related call to Poison Control Centers.  
  In the USA during 1998, there were 61, 813 cases of non-pharmaceutical toxicity in children under six years of age reported calls to Poison Control Centers. Of those cases, 3, 294 were related to toxic reactions to plants:  
        Total Plant Related Percent Plant Related  
    Number of Cases requiring Treatment at Health Care Facility. 61,813 3, 294 5.3%  
    The Outcome was "moderate effect". 5,409 223 4.1%  
    The Outcome was "major effect". 353 13 3.6%  
    The Outcome was "death". 0 0 0  
  The following categories of toxic substances were implicated in the above cited 223 cases of plant related toxic reactions which had outcomes classified as moderate:  
    Substance Implicated in the Exposure Percent of Outcomes with Moderate Effect  
    Amygdalin / cyanogenic 3 cases/ 223 1.3 %  
    Anticholinergic 4 cases/ 223 1.7 %  
    Cardiac Glycosides and Stimulants 13 cases/ 223 5.8 %  
    Dermatitis 74 cases/ 223 33.1 %  
    Gastrointestinal Irritants 38 cases/ 223 17.0 %  
    Oxalates 19 cases/ 223 8.5 %  
    Solanine 8 cases/ 223 3.6 %  
    Toxalbumins 1 cases/ 223 0.4 %  
    Non-toxic, Other, Unknown 63 cases/ 223 28.2 %  


Overview of Toxic Substances in Plants


Amygdalin / cyanogenic

Amygdalin a cyanogenic glycoside releases hydrogen cyanide when injested.Cyanide readily binds to enzymes and proteins containing iron, including hemoglobin, and myoglobin, It binds to the ferric iron of the mitochondrial cytochrome oxidase system, thus inhibiting oxidative phosphorylation and paralyzing cellular respiration. Prunus plants including peaches, plums, apricots, bitter almonds, chokecherries, and cherry laurels  



Scopolamine, competitively binds to (muscarinic) acetylcholine receptors at both peripheral (heart, salivary and sweat glands, GI tract), and central neuromuscular  receptors. Deadly nightshade,  mandrake.


  Cardiac glycosides and stimulants Cardiac glycosides are thought to inhibit the membrane bound Na+-K+- pump responsible for Na+-K+ exchange, this inhibition would result in reduced sodium exchange with potassium resulting in increased intracellular Na+  and Ca++ causing an  increase in the force of the myocardial contraction. Christmas rose,  foxglove, lily of the valley,  
  Dermatitis Allergic contact dermatitis, often results from repeated exposure to someone whose immune system is sensitive to the protein allergen. Those who are sensitive to one member of the Compositae plant family can become sensitive to other members of the plant family. Phytophotodermatitis is independent of immune system and requires skin to be exposed to direct sunlight. Poison ivy, poison oak, poison sumac  
  Gastrointestinal irritants Anthraquinones are important irritant substances which significantly alter gastro-intestinal motility. Bitterweed,  colorado rubberweed, copperweed.  
  Oxalates Oxalates consist of soluble oxalates and oxalic acid; poisonings are often attributed to small crystals of insoluble calcium oxalate which cause oral irritation when ingested. Dumbcane  
  Solanine Solanum alkaloids inhibits acetylcholinesterase from removing acetylcholine from neuromuscular junctions. Acetylcholine is the neurotransmitter. When an inhibitor of acetylcholinesterase such as solanine is present in the cleft, acetylcholine accumulates. Irish potato  
  Toxalbumins Toxalbumins are Phytotoxins that inhibit protein synthesis. Castor beans contain the toxalbumin ricin, and jequirity beans contain abrin. Castor bean and rosary pea, jequirity beans.  


Toxic House Plants

  Philodendron Genus.        
  Description: Climbing vines with aerial roots.  Leaves large and variable, the most common being heart-shaped.  
  Common Names: Philodendron.          
  Toxic Parts: Leaves, juices.  
  Symptoms: When ingested, causes painful burning of the lips,  mouth, tongue, and throat. May also cause reddening and inflammation of the skin, and itchiness.  
  Toxic Substance: Oxalates.  
  Toxic species of Phildendron plants:  
    P. cordatum - Heart leaf philodendron  
    P. scandens - Heart leaf philodendron   P. selloum - Lace tree philodendron      
      Philodendron selloum      
  Chrysanthemum Genus.        
  Common Names: Chrysanthemum, Daisy, Feverfew, Marguerite.      
  Description: Showy flowers in almost all colors except blue.  
  Toxic Parts: Leaves and stems.  
  Symptoms: Skin contact may cause dermatitis.  
  Toxic Substance: Sesquiterpene lactones allergens.  

  Scientific name: Hyacinthus orientalis .        
  Description:  Bulbous herbs with long, narrow leaves, often has flowers of white, yellow, red, pink or blue..  
  Common Names: Garden hyacinth.          
  Toxic Parts:  Leaves, juices, and hyacinth bulb dermatitis.  
  Symptoms: Ingestion causes stomach cramps, nausea, vomiting and diarrhea.  
  Toxic Substance: Oral toxicity due to alkaloid, bulb dermatitis caused by oxalate crystals.  

  Rhododendron species.        
  Description: Evergreen, semi-evergreen, or deciduous shrubs with a variety of colored flowers.  
  Common Names: Azalea, Rhododendron, Rhodora, Rosa Laurel, Rosebay.  
  Toxic Parts: Leaves and honey made from the flower nectar.  
  Symptoms: Burning in mouth, salivation, and diarrhea may occur.  
  Toxic Substance: Andromedotoxin, arbutin glucoside.  
  Toxic species of Rhododendron  plants:  
    Rhododendron occidentale - Azalea  


  Scientific Name: Caladium hortulanum.        
  Common Names: Angels' wings.          
  Toxic Parts: Leaves, roots, stems..  
  Symptoms: Ingestion can cause severe irritation to the mouth and throat, may also be an irritant to stomach and intestines.  
  Toxic Substance: Oxalates.  
  Scientific name: Digitalis purpurea.        
  Description: Erect, biennial herbaceous plant with soft oval, hairy green leaves that form a rosette. Clusters of pink-purple, tubular-shaped flowers, forming capsular fruit containing very many small seeds.  
  Common Names: Foxglove, dead-men's bells.          
  Toxic Parts: Leaves and seeds.  
  Symptoms: Nausea, severe vomiting, advanced heart rhythm disturbances, tachycardia, and ventricular fibrillation.  
  Toxic Substance: Contains digitallin and other glycosides which stimulate heart action. Has a very bitter taste so humans usually avoid ingestion. When ingestion occurs, outcome is often fatal.  
  Scientific name: Nerium oleander.        
  Description: Evergreen shrub or small tree with thick, gummy, clear sap; leaves opposite or whorled, simple, leathery, with smooth margins and conspicuous pinnate veins; flowers clustered at tip of twigs, 5-parted, funnel-shaped, white, pink, red, or yellow.  
  Common Names: Oleander.          
  Toxic Parts: All parts - green or dry.  
  Symptoms: Extremely toxic - a single leaf is considered potentially lethal to humans. Symptoms begin several hours after ingestion, and include dizziness and drowsiness, increased pulse rate, cold extremities, abdominal pain, nausea, weakness and vomiting.  
  Toxic Substance: Nerioside, oleandroside, saponins, cardiac glycosides.  


Toxic Holiday House Plants

  Scientific Name: Ilex aquifolium.

Family:   :

  Description: An evergreen tree 1-20 meters high. Leaves are dark green, shining, hard, thorny on the young branches. Flowers are small, white, rosy, fragrant; situated at the base of the leaves. Fruits are bright red or yellow berries of 8 mm diameter.  
  Common Names: European holly, English holly, Oregon holly, sparked holly, Christmas holly, crocodile holly, prick holly, common holly.  
  Toxic Parts: Leaves, bark, berries contain active principles; no information available on roots.  
  Symptoms: Ingestion of berries may cause nausea, vomiting, abdominal pain and diarrhea. Stupor and drowsiness have been seen in children after ingestion of large quantities of berries. Although lethal cases have been reported in older literature there are no recent reports of severe poisonings. Ingestion of Ilex aquifolium berries is mostly associated with gastrointestinal symptoms.  
  Toxic Substance: Contains several toxins: saponin, phenolic compounds, terpenoides, sterols, alkaloids, anthocyanines. The exact mode of action is unknown. The gastrointestinal symptoms may be due to the saponin. However, no specific toxin responsible for the symptoms has been identified. .  
  Toxic Dose: Ingestion only route of poisoning. Hospitalization may be required if large amounts have been ingested. Intoxications are almost exclusively seen in children after ingestion of berries from Ilex aquifolium cultivated in parks, gardens, or when branches with berries are used ornamentally in homes.  
  Scientific Name: Solanum pseudocapsicum

Family:   :

  Description: Shrub with alternate, simple leaves; flowers 5-parted, white; fruit a bright orange-red (or rarely white or yellow) berry.  
  Common Names: Jerusalem cherry; christmas cherry; tom thumb; winter cherry.  
  Toxic Parts: The toxin is found throughout the plant but especially in the unripened fruit and leaves.  
  Symptoms: Nausea, vomiting, salivation, drowsiness, abdominal pain, diarrhea, weakness, and respiratory depression.    
  Toxic Substance: Solanocapsine and other alkaloids  
  Scientific Name  : Phoradendron leucarpum and Viscum Album      
  Description: Mistletoe is a partial parasite growing on many types of trees. Its toxicity may vary depending on the tree it grows on.  
  Common Names:  American and European Mistletoe.  
  Toxic Parts: Leaves, stems, and berries.    
  Symptoms: Body weakness, blurred vision, vomiting or nausea, abdominal pain (lower stomach), irregular heartbeat (or slow),  low blood pressure, drowsiness, and convulsions.  
  Toxic Substance: Tryamine and phoratoxin for Phoradendron genus and Viscotoxin for Viscum genus  
  Toxic Dose: Children sometimes eat the berries leading to mild to severe stomach ache. The Viscum genus is more toxic than the Phoradendron genus. Reactions following mistletoe ingestion are very variable, serious toxifications are rare but even fatal poisonings have been reported for both human and pets.  







  Poison Codes  
  Amygdalin / cyanogenic  
  Cardiac Glycosides and Stimulants  
  Gastrointestinal Irritants  

  Foxglove photo  
  Oleander, Philodendron, Hyacinthus, Rhododendron,  
  Oleander photo  
  Chrysanthemum, Caladium  
  Jerusalem cherry  
  Jerusalem cherry  
  Jerusalem cherry  
  Jerusalem cherry image  
  Mistletoe image  
  Holly image