Outdoor Flowers and Plants Poisonous to Children

Household gardens, yards, parks and recreational areas contain many ornamental plants and weed species that may be poisonous to children if eaten. Others may cause severe skin reactions or allergic responses if they come in contact with the skin, sometimes with very serious symptoms.

Children are vulnerable to plant poisoning because of their naive curiosity and their inability to recognise potentially dangerous plants. Some toxic plants have attractive berries or fruits which children may eat. Others have toxic sap or irritating protective spines which may severely irritate the mouth or sensitive skin.

Ten Common Poisonous Outdoor Flowers and Plants

In New Zealand, the National Poisons Information Centre recognises ten common ornamental plants and weeds which are most often involved in childhood poisonings after ingestion or skin contact with harmful plant parts or secretions:

1. Arum Lily (Zantedeschia aethiopica). All parts of this plant are toxic, though children are most attracted to eat the appealing spikes of bright orange berries. Only a tiny amount can cause a severe burning sensation in the mouth and if swallowed can cause stomach pains, vomiting and diarrhoea.
2. Black Nightshade (Solanum nigrum). Solanum species, including potatoes and tomatoes, contain mildly toxic chemicals, particularly in the green parts such as leaves and unripe fruits. Ingestion of unripe fruits may result in stomach pains and vomiting though ripe berries of black nightshade, which resemble blackcurrants, are not usually toxic.
3. Spurge (Euphorbia species). Spurges are a very common group of garden plants whihc includes the popular house plant Poinsettia. All parts of the plant are poisonous if eaten. The milky sap can also burn the delicate membranes inside the mouth.
4. Iris (Iris foetidissima). All Iris species are poisonous, but the stinking iris is most often reported because it presents attractive and prominent orange seeds when the fruit capsules open.
5. Oleander (Nerium oleander). All parts of oleander are extremely poisonous and, though the bitter taste often deters children from swallowing it, ingestion of only a tiny amount can be extremely dangerous.
6. Agapanthus (Agapanthus species). The slimy mucilaginous sap of Agapanthus is a skin irritant which can cause a burning sensation in the mouth if eaten.
7. Stinging Nettles (Urtica species). Stinging nettles are common weeds and can cause considerable discomfort after contact with the stinging spines. Ongaonga, the notorious giant tree nettle (U. ferox), native to New Zealand, is particularly unpleasant because the large ‘stings’ can cause numbness and pain which can persist for several days. In severe cases hospitalisation is necessary.
8. Poison Hemlock (Conium maculatum). Hemlock is one of the most poisonous plants. All parts of the plant are extremely toxic. Young plants and seeds may be confused with parsley, dill, celery or other umbelliferous herbs, though larger plants can be distinguished by purple marking on the stems and an unpleasant smell.
9. Foxglove (Digitalis purpurea). All parts of the foxglove are extremely toxic. The toxin, digitalin, is a powerful heart stimulant. Children may be at risk from ingesting pollen after playing with the ‘finger-glove’ flower trumpets.
10. Wax Tree (Toxicodenron succedaneum). Sometimes called the Japanese wax tree or varnish tree, this species is related to the notorious poison ivy (T. radicans) which can cause severe skin irritation in susceptible people, occasionally requiring hospitalisation.

What to do in Cases of Suspected Plant Poisoning

• Apply basic first aid procedures.
• Keep the patient calm.
• Do not induce vomiting.
• Do not give the patient anything to drink.
• Get medical assistance.
• Identify the suspected plant and keep a sample if practical.

In New Zealand, the National Poisons Information Centre operates an urgent 24 hour poisons hotline – 0800 POISON (0800 764 766).

Outside New Zealand, refer to local medical agencies or telephone directories for advice.

Sources

Poisonous Plants in New Zealand. National Poisons Centre, Dunedin, New Zealand (PDF: accessed June 2010).

Plants in New Zealand Poisonous to Children, by W.R. Sykes (2002). Landcare Research New Zealand. (PDF: accessed June 2010).