About 1000 species of plants in Australia are known to be toxic to humans and fauna. Some may cause skin and eye irritation, rashes and other forms of discomfort, but there are those which, if ingested, may cause vomiting and diarrhoea and worse, if medical attention is not obtained.
The Oleander was a common plant in Australia, but has reduced in number due to increasing knowledge about its toxicity. If any part of the plant is ingested it can be fatal, especially for children. Fortunately, the leaves are very bitter, so children are not generally tempted to eat them. None the less, these plants should not be planted in areas where children play.
Deadly Nightshade, also known as “devil’s berries” or “death cherries” are very poisonous and can cause hysteria, hallucinations, erratic behaviour and delirium. Ingestion of a single leaf can be fatal to adults.
Angel’s Trumpets may appear pleasant and are quite common in Australian gardens, but they are highly toxic. Ingesting the trumpet flowers can cause paralysis and even death.
The Strychnine Tree is native to South East Asia and Australia. Its small orange berries are neurotoxic and can cause convulsions, paralysis and death. In very low levels, it is known to improve appetite and is sometimes used in herbal medicines. It is also used as rat poison!
The Moreton Bay Chestnut (or blackbean tree) is native to Queensland and New South Wales, and thrives in coastal rainforests, where it is grown as a valuable source of timber. Between March and May, it produces toxic seeds in large pods.
Two plants with toxic sap are Milky mangrove and Spurge. Both produce very unpleasant irritations if the sap comes into contact with human skin and are to be avoided, especially around the eyes, nose or mouth.
The Nettle family of plants are native to Australia and have stinging hairs on the leaves, stems or fruit may cause allergic reactions, swelling and severe pain. Antihistamine tablets and protective gardening gloves should be on hand if working in an area with nettle plants.
There are also a number of flowering garden plants which have been introduced to Australia, with toxic leaves, flowers and/or berries. These have been known to harm animals – Hoya, Daphne, Hydrangea, Cassia and Buxus.
Image credit of Angel’s Trumps used as feature image: CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=142315