Poisonous plants Dr Trisha Macnair Knowing which plants are safe to eat could save your life. Mushrooms can be particularly tricky to identify and the symptoms of poisoning can be mistaken for gastroenteritis, meaning victims often fail to seek medical help.

In this article

Mushrooms Other plants

Houseplants Protecting pets

Keep risks in perspective

It's easy to confuse edible mushrooms with poisonous ones. The Amanita family, which includes the death cap fungus (Amanita phalloides) and destroying angel (Amanita virosa), can cause particularly nasty symptoms.

After several hours, the victim is gripped by sudden, severe seizures of abdominal pain, persistent vomiting and watery diarrhoea. They may seem to recover, but then, after a couple of days, develop liver, kidney and heart failure.

There is no antidote or specific treatment, and the mortality rate with some Amanita species is between 50 and 90 per cent.

These mushrooms are primarily identified by a 'veil' or hood that completely covers the immature mushroom. The adult mushroom has a cup around the base, a partial veil that may form a ring on the upper stalk, free or slightly attached white/cream coloured gills and a white spore print.

However, some of these identifying characteristics are delicate and can be removed by rain, wind or animals.

To reduce your risk of poisoning, only eat mushrooms you can identify with absolute certainty.

There are plenty of other poisonous plants, some of which you might not imagine could harm you.

Rhubarb, for example, contains oxalate crystals and can cause poisoning when large quantities of raw or cooked leaves are eaten.

Rhubarb also contains chemicals called glycosides, the same group of compounds that make foxgloves and lily-of-the-valley dangerous. These are found low in the stalks, so only ever use the middle of the stalks.

Sweet pea seeds are particularly poisonous. In India, where the related grass-pea is still used for flour, a condition called neurolathyrism can lead to paralysis.

There are many other examples, from laburnum to poppies, deadly nightshade to aconitum.

Don't forget to check the plants inside your home too. The leaves of the Swiss-cheese plant (split-leaf philodendron) can cause problems if chewed by a baby.

General symptoms of poisoning include blistering of the skin, hoarseness, irritation of the mouth, and allergic reactions and itching.

Animals are just as vulnerable as humans and sometimes less discerning about what they chew. There have been reports of dogs, cats, and even pet monkeys becoming ill after eating leaves and green berries from ivy, for example. These contain another glycoside, causing mouth, stomach irritation and even coma and death when consumed in large quantities.

Poinsettia plants are another potential danger. All parts may be toxic but in particular the milky sap can cause skin, mouth, eye and stomach irritation. Affected animals typically shake their heads, salivate, and paw or rub their mouth or eyes.

Before you panic and rush off to convert your garden into a Japanese art form of stones and water, keep things in perspective. Research has shown the risk of harm from plant poisons is low - less than one in 10 million.

Why not start a weekly walk with your children to educate them about the beauty and the beasts in your garden?

This article was last medically reviewed by Dr Rob Hicks in July 2006.