Menu Close

Meet five of the UK’s most poisonous plants

Cuckoo pint. Phil Sellens, CC BY

Serious poisoning by plants is very rare in the UK so the death of a gardener in Hampshire after brushing against a deadly flower was extremely unusual.

Despite the British countryside’s genteel reputation there are a surprisingly large amount of poisonous plants growing both in the wild and in gardens. Some just cause discomfort, but others have the potential to kill. Here are five to watch out for.


Wolfsbane belongs to the plant genus Aconitum, a group of plants which are all poisonous. The native plant, also called monkshood, has large leaves with rounded lobes and purple hooded flowers. Although it can be found throughout the UK, cases of accidental poisoning are very rare. Still, people plant it in their gardens, possibly unaware of the potential hazard.

Beautiful but deadly: Wolfsbane. Randi Hausken, CC BY

It is one of the most toxic plants that can be found in the UK, the toxins in the plant can cause a slowing of the heart rate which can be fatal and even eating a very small amount can lead to an upset stomach. But its poison can also act through contact with the skin, particularly if there are open wounds. The roots are thought to be especially poisonous but even so, people have been known to eat the roots and survive so it is very difficult to know how much contact is needed to kill someone.

As with any poisonous plant, the best way to avoid it is to learn to recognise what it looks like. Once you can recognise it then you can make sure you don’t eat it and only handle it with gloves on.


Foxglove grows in woodlands and hedgerows. It is a common garden plant, popular due to its tall purple flowers. Its large soft leaves grow in a rosette.

Foxglove. Brian Eastop, CC BY

If any part of the plant is eaten it causes vomiting and diarrhoea together with other unpleasant symptoms, and just like wolfsbane it can slow the heart down causing heart attacks. Even contact can cause irritation to the skin.

However, foxglove has saved more lives than it has cost as drugs derived from the plant are used to treat heart conditions.

Cuckoo pint

Cuckoo pint. Phil Sellens

The cuckoo pint (Arum maculatum) or lords and ladies, is found growing in woodlands and hedgerows. Its flowers are poker-shaped surrounded by a green leaf-like hood but it is the bright red and orange berries of this plant that are poisonous.

If eaten, the berries cause irritation in the mouth and throat which leads to swelling and pain and can result in difficulty breathing. It also causes an upset stomach.

Deadly nightshade

As its name suggests, deadly nightshade is another poisonous plant. Deadly nightshade is most common in central, southern and eastern England but is also found less commonly in other parts of the UK. It is a shrubby plant with purple bell-shaped flowers and shiny black berries.

Deadly nightshade. Tom Oates, CC BY-SA

In the first instance poisoning results in symptoms including dilated pupils, loss of balance and a rash but it can eventually lead to hallucinations and convulsions. Atrophine, a drug extracted from nightshade, is used in eye examinations to dilate the pupil. It’s even used as a nerve gas antidote.


Hemlock isn’t native to the UK but can be found in most areas. It grows in ditches and riverbanks and in disturbed area such as waste ground and rubbish tips.

Hemlock. Mick Talbot, CC BY

Hemlock is a tall green plant with purple spots on its stem and leaves similar to the carrot plant, it has white flowers. If it is eaten hemlock causes sickness and in severe cases it can kill by paralysing the lungs.

Want to write?

Write an article and join a growing community of more than 185,200 academics and researchers from 4,982 institutions.

Register now