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The vast majority of the nearly 400,000 plant species that exist worldwide are not dangerous to humans and animals. On the contrary, we could not exist without plants.

So, on average, you don’t have to be afraid of anything. In fact, there is only a limited number of smart plant species that have learned to protect themselves against damage and disease with poison, or through allergic reactions.
It is therefore important to keep an eye on that group of plants, because they can cause itching, nausea, rash and sometimes paralysis. We do not consider the plants that cause a limited allergic reaction here, because there are far too many, and because the allergic reaction is often very personal.
It is also good to know that certain poisons from plants are also used because of their medicinal properties. Information about this can be found in the article: ” Medicinal plants ”


Poisoning is most common in children aged one to four years. In that growth phase, they put everything they can get their hands on in their mouths, including parts of plants: leaves, stems, beautifully colored fruits, etc. Young pets also gnaw on everything. It has everything to do with their still small body and barely built up resistance. Extra caution is advised. The symptoms of poisoning include: sudden vomiting, abdominal pain, colic, convulsions, diarrhoea, pale tongue, swelling in the mouth and throat. And of course skin irritations.
In the event of (presumed) poisoning, you immediately call 112, your GP or the NVIC Institute 088-7558000.
For example, take a look at the website of parents of now


It’s just helpful to know which garden and greenhouse plants are among the most poisonous. You are automatically more alert during maintenance, and of course also when children or pets are playing outside. In practice, however, not much happens as long as plant parts or plant juices are not actually consumed.


We distinguish four groups:

  1. Indoor plants
  2. trees
  3. Shrubs
  4. Perennials
  1. Indoor plants
    • Honey locust ( Euphorbia milii )
      Especially the white milky juice is poisonous. Symptoms include: abdominal pain, headache, vomiting, swelling in the throat. In severe poisoning: heart (rhythm) disorders, shock symptoms.
    • Ficus species ( Ficus )
      The leaves are especially poisonous. When swallowed, sometimes watery, often itchy eyes, difficult breathing, a runny nose. Diarrhoea, abdominal cramps and skin irritation also occur.
    • Poinsettia ( Euphorbia pulcherrima )
      Poisonous in all parts. Symptoms after ingestion are: vomiting and diarrhoea. On contact: skin rash, and red eyes after rubbing. May be harmful to kidneys and nervous system.
    • Dieffenbachia species ( Dieffenbachia )
      Toxic in all parts. If swallowed or put in the mouth: swelling of the tongue and oral mucosa (palate), increased salivation, difficulty in swallowing, difficulty breathing. After touch: painful irritation.
    • Slip plant ( Begonia maculata )
      The sap is poisonous. Causes skin irritations and when ingested, vomiting and mucous membrane inflammation.
    • Aloe ( Aloe vera )
      The juice is not toxic to humans, but it is to pets. It can cause vomiting and diarrhea in pets.
    • Arum ( Syngonium )
      Juice and berries are poisonous. Effects: diarrhea, cramps, mucosal inflammation.
    • Hole plant ( Monstera deliciosa )
      This air purifier is slightly toxic in all parts. Sap on skin and mucous membranes causes significant irritation spots and swelling. Much more toxic to pets than to humans, in particular.
    • Elephant Ear (Alocasia )
      Slightly poisonous. May cause irritation to skin and mucous membranes.
    • Dragon ‘s blood tree ( Dracaena )
      Not toxic to humans (it’s even a good air purifier), but the sap is toxic to pets.
    • Zamioculcas or house palm ( Zamioculcas zamiifolia )
      The sap of this succulent plant is slightly poisonous. May irritate skin on contact. Small children, dogs and cats are especially sensitive to it.
  2. trees
    • Velvet tree or vinegar tree (Rhus typhina)
      The sap, leaves and fruits are poisonous. Symptoms: intestinal problems.
    • Juice from leaves and fruits is highly poisonous. Berries are life-threatening. Symptoms: vomiting, diarrhea, drowsiness, drowsiness.
    • Toxic in all parts. Symptoms: cramps, respiratory failure, hysteria.
    • (Aesculus hippocastanum)
      Toxic are seeds, leaves, fruits, bark. Effects by ingestion: anxiety, restlessness, confusion, flushed face, thirst, abdominal pain, vomiting.
    • Toxic are juice from leaves, bark, seeds (the pit of the fruit), sometimes even irritation when touched. Especially the berries are dangerous for small children because they are so beautiful red. Symptoms: inflammation in the stomach and intestines, dilation of the pupils, cramps, dizziness, purple spots on the skin, irregular pulse.
    • Tree of Life (Thuja)
      All parts are poisonous if ingested. Symptoms: cramping, stomach and intestinal problems.
    • Golden rain (Laburnum anagyroides)
      Very poisonous in all parts, especially the seeds (pods). Ingesting a few seeds can be deadly. Symptoms: burning sensation in mouth and throat, vomiting, diarrhoea, restlessness that progresses to paralysis.
  3. Shrubs
    • Azalea (Rhododendron)
      Flowers and leaves are poisonous. Symptoms upon ingestion: watery eyes, runny nose, heavy saliva production, mucosal inflammation, vomiting, slow pulse (heart rate).
    • Broom (Cytisus)
      Toxic in all parts. Symptoms upon ingestion: cramps, vomiting, heart disorders, unconsciousness or excitement.
    • Wisteria (Wisteria)
      Twigs, pods, roots and seeds are poisonous. Symptoms after ingestion: vomiting, abdominal cramps, vomiting and diarrhea.
    • Boxwood ( Buxus )
      Toxic in all parts. phenomena; vomiting, diarrhea, convulsions after ingestion. Contact can also cause skin irritation and inflammation.
    • Dwarf medlar (Cotoneaster)
      Poisonous are leaves, seeds, roots. Symptoms after ingestion: stomach and intestinal disorders.
    • Thorn apple ( Datura stramonium )
      Effect of hallucinations.
    • Especially the black berries, but also the leaves are poisonous. Symptoms: vomiting, diarrhoea, temperature rise, abdominal pain, convulsions, poor concentration and sometimes also skin irritation with itching.
    • Oleander (Nerium oleander)
      This container plant is poisonous in all parts: one leaf can be deadly for a small child. Symptoms: stomach pain, intestinal inflammation, diarrhea, vomiting, poor heart function.
    • Pepper tree (Daphne mezereum)
      Juice from bark and berries is very poisonous. Ingestion of a few berries can be fatal in a small child. Symptoms: burning sensation in mouth, throat, esophagus and stomach, diarrhoea, blisters, abdominal cramps.
    • Rhododendron (Rhododendron) all parts are poisonous. Symptoms: abdominal pain, convulsions, increased saliva, muscle weakness, low blood pressure.
    • Snowberry (Symphoricarpos albus)
      The berries are poisonous. Symptoms: mucosal inflammation, vomiting, diarrhoea, also unconsciousness.
    • Privet (Ligustrum)
      Poisonous are leaves, berries and bark. The juice can cause skin irritation when touched. Symptoms upon ingestion: vomiting, diarrhea, convulsions, circulatory disorders.
    • Wood vine (Clematis) Toxic
      in all parts. Juice can cause skin irritation when touched. Other symptoms: mucosal inflammation, stomach and intestinal disorders, blistering.
    • Leaves, bark and seeds are poisonous. When ingested, the symptoms are often: vomiting, intestinal cramps, also drowsiness.
  4. Perennials and herbaceous plants
    • Monkshood (Aconitum)
      Toxic in all parts. Symptoms: stomach and intestinal disorders and stomach pain, vomiting, numbness, heart complaints, also skin inflammation when touched.
    • Buttercup ()
      The sap of boat flowers is poisonous when ingested and causes skin irritations when touched. Symptoms: gastroenteritis, also nervous disorders.
    • Anemone (Anemone)
      Toxic leaf and sap. Effects: burning sensation in mouth and throat, intestinal problems, vomiting, diarrhoea, skin irritation when touched.
    • Christmas Rose or Hellebore (Helleborus)
      Toxic in all parts. Symptoms: burning sensation in mouth and throat, vomiting, diarrhoea, stomach pain, impaired heart function.
    • Lily of the Valley (Convallaria majalis)
      A bulbous plant. Toxic in all parts. Symptoms: nausea, vomiting, diarrhoea, abdominal cramps, fainting and heart failure.
    • Marigold (Caltha palustris)
      Slightly poisonous in all parts. Symptoms: dizziness, vomiting, diarrhea. Ingestion sometimes affects kidney function.
    • Sleeping bulb/Poppy (Poppy)
      Toxic in all parts. Symptoms: constricted pupils, flushed face, difficulty breathing, impaired heart function.
    • Autumn crocus (Colchicum autumnale)
      All species are very poisonous when ingested. Symptoms: burning sensation in mouth and throat, stomach pain, vomiting, abdominal cramping, diarrhoea, impaired breathing, strong saliva production.
    • Giant Hogweed (Heracleum mantegazzianum)
      Sap is poisonous, strongly blistering in sunlight when the plant is touched (juice and stinging hairs).
    • Spurge (Euphorbia
      ) Toxic in all parts (the milky juice!) Symptoms: vomiting, diarrhea and other gastrointestinal disorders, cramps, blisters, sometimes also eye damage.
    • Foxglove (Digitalis purpurea)
      Toxic in all parts. Symptoms: vomiting, diarrhoea, cardiac arrhythmias, headache, inflammation of the digestive tract.
    • Larkspur (Delphinium)
      Toxic in all parts, especially the seeds. Symptoms: Burning sensation in the mouth that progresses to numbness and tingling in the mouth (tongue) and lips.
    • Miracle Tree (Ricinus communis)
      Phenomena; abdominal cramps, heart rhythm disturbances.
    • Wild man ‘s herb (Pulsatilla vulgaris)
      Juice is poisonous to the touch and ingestion. Symptoms: stomach and intestinal inflammation, paralysis symptoms.


In addition to the above lists, there are still plenty of plants that can only be harmful in the flowers. We mention them separately because they are often used in bouquets on the table. These are buttercups, hydrangea, hyacinth, crocus, lily, narcissus, Solomon’s seal, tulip and spurge.
When dogs and cats have eaten something wrong, they often look for grass themselves or else to make themselves vomit. Basically just leave it alone!


Before, every farmer knew what was dangerous for his horses, sheep and cows. That knowledge has also subsided somewhat due to the hobby-moderate nature of many animal keepers. Caution with regard to horses, cattle, sheep and goats is also advised there.
Toxic in more and less sizes

  • Spotted hemlock (Conium maculatum)
  • Autumn crocus (Colchicum autumnale)
  • Laburnum anagyroides (Laburnum anagyroides)
  • Bracken (Pteridium aquilinum)
  • American bird cherry (Prunus serotina)
  • Oak (Quercus)
  • Ivy (Hedera)
  • Lupine (Lupinus)
  • Nightshades (Solanum, also wolfcress)
  • Giant Hogweed (Heracleum mantegazzianum)
  • Rhododendron (Rhododendron)
  • Comfrey (Symphytum officinale)
  • Foxglove (Digitalis purpurea )
  • Maple (Acer)
  • Ragwort (Jacobaea vulgaris)
  • Rock heath ( Pieris )
  • St John’s wort (Hypericum perforatum)
  • Water hemlock (Cicuta virosa)
  • Mellow goose foot or White goose foot (Chenopodium album)

For your reassurance
It may seem that many plants are poisonous or irritating in one way or another, but that is certainly not the case. Most plants are not annoying to people and pets. And while a few are really annoying, you have to consume a lot to get into big trouble. Still, a little extra attention and attentiveness can’t hurt.


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