Recognising and avoiding the most dangerous poisonous plants
A few plants in Central Europe are so poisonous that even small amounts or mere skin contact can have serious consequences: poison hemlock, cowbane, giant hogweed, deadly nightshade, yew, autumn crocus, lily of the valley, monkshood, foxglove and laburnum. Here you learn their warning features, the typical confusions (for example with wild garlic) and what to do at once if poisoning is suspected.
- Learning: a few hours, ideally on a guided walk
Explained simply
Most plants outdoors are harmless. But a few are so poisonous that even one leaf, a few berries or even touching them can be dangerous. You should know these few plants, just as you know that a hot stove burns.
Some of them look like plants you can eat. Autumn crocus and lily of the valley have leaves that look like wild garlic. Hemlock looks like wild carrot or parsley. And the huge giant hogweed burns your skin if its sap gets on it and then the sun shines.
If someone has eaten something poisonous, stay calm: take remains out of the mouth, do not make them vomit, take a piece of the plant and call the poison line. If the person is breathing badly, having seizures or is no longer properly awake, call the ambulance at once.
How it works
Plants cannot run away. That is why many protect themselves with poisons against animals that want to eat them. These substances act on nerves, heart, gut or skin. With the plants described here, the dangerous amount for people is small, and for children even smaller.
Hemlock and cowbane attack the nerves and can cause paralysis or seizures. Foxglove and lily of the valley contain substances that act on the heart. Autumn crocus contains a cell poison whose effect often only begins after hours. Monkshood acts on nerves and heart, and its poison can also be absorbed through the skin.
Giant hogweed is different: its sap is dangerous mainly on the skin rather than when eaten. Together with sunlight it causes skin damage that looks like burns – often only hours later, with blisters that take a long time to heal.
What really matters
The most important group are the umbellifers: plants with many small, mostly white flowers in umbrellas. They include chervil, parsley and wild carrot, but also the deadly hemlocks. Poison hemlock has a smooth stem with reddish-brown spots and smells of mouse urine when crushed. For beginners: umbellifers are not gathered at all.
With wild garlic you check every leaf on its own. Wild garlic has its own stalk for each leaf and a matt underside. Lily of the valley usually has two leaves tucked into each other at the base and a glossy underside. Autumn crocus has stalkless leaves in a cluster, often with a seed capsule in the middle. The garlic smell is unreliable, because your fingers smell of garlic after the first real leaf.
Also memorise the conspicuous ornamental and garden plants: yew with red cups, laburnum with yellow, hanging flower clusters, monkshood with blue helmet flowers and foxglove with purple bells. They often grow exactly where children play.
Safety: what to watch out for
If poisoning is suspected, calm and the right order are what count. Take plant remains out of the mouth, let the person spit, give at most a few sips of water. Do not induce vomiting: vomit can get into the lungs, and some poisons do damage again on the way back up. Milk, salt water or other home remedies do not help either and can cause harm.
In Austria call the Poison Information Centre: +43 1 406 43 43, around the clock. Doctors there tell you whether there is danger and what to do. Have ready: which plant, which part, how much, when, the person's age and weight and how they are. Germany has regional poison information centres. With breathing problems, seizures, reduced consciousness or a racing heart call 144 or 112 at once.
After contact with giant hogweed wash the skin at once with plenty of soap and water and keep the area out of the sun for several days. With blisters or large areas see a doctor. If sap has got into the eye, rinse at once with plenty of water and get medical help.
When it makes sense – and when not
You need this knowledge whenever you are outdoors, look after children, plan a garden or want to gather wild plants. It is a foundation for avoiding – not instructions for eating similar plants. Recognising a poisonous plant does not tell you that the plant next to it is edible.
For a real emergency: plants are almost never what saves you. They provide little energy and carry big risks. Water, warmth and getting help are much more important than a herb salad of uncertain leaves.
Good to know
The German Federal Institute for Risk Assessment stresses that there are only a few truly highly poisonous plants in Central Europe. Most poisoning cases in children end harmlessly because they only taste a little. That is exactly why it pays to know the few dangerous species well instead of mainly being afraid.
Giant hogweed is an introduced species and is on the EU list of invasive species. It is best to report larger stands near paths or playgrounds to the local council. Only people with protective clothing and experience should tackle it.
Step by step
Umbellifers: hands off
Plants with many small white flowers in umbrella-shaped umbels (like wild carrot, chervil, parsley) have deadly relatives. Poison hemlock grows up to about 2 metres, has a smooth stem with reddish-brown spots and smells unpleasantly of mouse urine when crushed. Cowbane grows on banks and in marshes; its thick rootstock is hollow inside and divided into chambers by cross walls. Both are deadly even in small amounts.
Caution: Never eat white umbels unless you are absolutely certain.
- 1
Umbellifers: hands off
Plants with many small white flowers in umbrella-shaped umbels (like wild carrot, chervil, parsley) have deadly relatives. Poison hemlock grows up to about 2 metres, has a smooth stem with reddish-brown spots and smells unpleasantly of mouse urine when crushed. Cowbane grows on banks and in marshes; its thick rootstock is hollow inside and divided into chambers by cross walls. Both are deadly even in small amounts.
Never eat white umbels unless you are absolutely certain.
- 2
Recognise giant hogweed and keep away
Giant hogweed usually grows 2 to 4 metres tall, has huge, deeply cut leaves, a thick, red-spotted stem and white umbels that can be bigger than a plate. It likes stream banks, roadsides and waste ground. Keep away, especially with children. If you had contact, wash the skin at once with soap and water and keep it out of the sun for several days; see a doctor if blisters form.
- 3
Poisonous berries and yew
Deadly nightshade bears single, glossy black, cherry-sized berries on a green star of five calyx points. Yew is a conifer with flat, soft needles and red cups open at the top; needles, bark and seeds are highly poisonous, for people and horses alike. Both can be deadly even in small amounts.
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Avoid the wild garlic confusion
Wild garlic: each leaf comes out of the ground singly on its own stalk, the underside is matt. Lily of the valley: usually two leaves, rolled into each other at the base, coming from one stem, underside glossy. Autumn crocus: leaves without a stalk, coming out of the ground in a cluster in spring, often with a seed capsule in the middle. Check every single leaf – one poisonous leaf in the bunch is enough for severe poisoning.
The smell test is unreliable – hands quickly smell of garlic.
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Monkshood, foxglove, laburnum
Monkshood has dark blue, helmet-shaped flowers on tall stems and grows in damp mountain meadows and gardens; it is considered one of the most poisonous plants in Europe, and its poison can also be absorbed through the skin – do not pick it. Foxglove bears purple bells on a long spike; before flowering its leaves resemble those of other herbs. Laburnum is an ornamental shrub with hanging yellow flower clusters and bean-like pods; the seeds are dangerous for children.
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Apply the basic rule
Only eat what you recognise reliably by several features – never because of a single resemblance. "Edibility tests" by tasting do not detect many deadly poisons and are no substitute. Teach children to examine plants with their eyes only, and remove yew, laburnum and monkshood from play areas or fence them off.
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If poisoning is suspected: act correctly
Take plant remains out of the mouth and let the person spit, give at most a few sips of water. Do not induce vomiting, no milk, no home remedies. In Austria call the Poison Information Centre (+43 1 406 43 43) and say what, how much, when, and how old and heavy the person is. Take a piece of the plant or a photo with you. With breathing problems, seizures, reduced consciousness or a racing heart call 144 or 112 at once.
Germany has regional poison centres; when in doubt always call 112.
Common mistakes
- Mistaking white umbels for wild carrot or chervil
- Pulling up wild garlic in clumps instead of checking leaf by leaf
- Relying on the smell test
- Removing giant hogweed with bare hands or in shorts
- Inducing vomiting or giving milk when poisoning is suspected
Quick view
Materials
Field guide to wild plants (for your region)
A book does not replace practice with a knowledgeable person
Identification apps can be wrong – never rely on them alone
Sturdy work gloves
In case you have to get close to giant hogweed or monkshood
When handling flood mud or chemicals, also wear waterproof gloves.
Mobile phone
For the poison line and a photo of the plant
The battery drains quickly in cold and with continuous screen and GPS use.
Do not plan on it as your only means of navigation or emergency calls.
Resealable food bags
To take a piece of the plant to the doctor
Use only bags intended for food; do not use with boiling water unless the manufacturer explicitly allows it.
Suitable for
- Everyone who spends time outdoors or looks after children
- Preparation for gathering wild plants
- Gardens, parks, forest edges, banks and mountain meadows
Not suitable for
- As permission to eat similar-looking plants
- Medical treatment of poisoning
Prerequisites
- Basic rule: nothing unknown is eaten
- Knowing the emergency numbers (112, in Austria 144 and VIZ)
How it works
Poison works by dose – but with these plants the dangerous dose is small. Instead of learning all poisonous plants, you memorise the few truly dangerous ones, especially those that look like edible plants. The umbellifers (hemlock, hogweed) and the wild garlic confusions are the most common traps. Hence the rule: only people who really master umbellifers gather them.
Advantages
- A few species cover the biggest dangers
- Protects children, pets and you
- Foundation for any safe gathering
Disadvantages
- Similarities remain treacherous despite learning
- Features change with the season (leaf, flower, fruit)
Deep knowledge
Background
The German Federal Institute for Risk Assessment lists monkshood, autumn crocus, laburnum, yew and deadly nightshade among the few highly poisonous plants of Central Europe. Every spring poison centres report poisonings from autumn crocus or lily of the valley mistaken for wild garlic – some of them fatal.
Giant hogweed comes from the Caucasus and is on the EU list of invasive alien species. Its effect on the skin is caused by substances in the sap that damage the skin together with UV light.
Variants
- Garden and playground check
- Walk once through your garden, kindergarten or playground with this list. Yew, laburnum, monkshood and foxglove are popular ornamental plants – often nobody knows they are there.
- Reporting giant hogweed
- Giant hogweed is an invasive species. You can report larger stands near paths or playgrounds to the local council instead of tackling them yourself.
Common mistakes
- Mistaking white umbels for wild carrot or chervil
- Pulling up wild garlic in clumps instead of checking leaf by leaf
- Relying on the smell test
- Removing giant hogweed with bare hands or in shorts
- Inducing vomiting or giving milk when poisoning is suspected
Limits and risks
- Not a complete list of all poisonous plants
- Features are simplified – when in doubt: do not eat, do not touch
- First aid at lay level only
Material alternatives
Derived from material properties: a substitute must have all relevant properties. Observe the notes on the substitute.
- Mobile phone
- Headlamp / flashlight, Battery lantern / LED light
- Resealable food bags
- Single-wall stainless steel bottle (Heat only single-wall bottles without paint/plastic; remove the lid before heating.), Double-wall insulated bottle (Never heat directly.), PET bottle (clear, max. 2 litres) (Do not heat or place in a fire.), Food-grade water container (Only use containers that never held chemicals or fuel.), Airtight food-grade storage container (Fill only when clean and completely dry; never use containers that previously held chemicals.), Collapsible water container or bag (Protect from sharp objects.), Food-grade water bag (Use only for drinking water, never for chemicals or fuel.), Fermentation jar or crock (Use only food-grade containers of glass, food-safe glazed stoneware or food-grade plastic – no metal containers for acidic food.)
Results come exclusively from structured entries. No improvised instructions are generated.
Sources
Bundesinstitut für Risikobewertung (BfR) (2017): Risiko Pflanze – Einschätzung und Hinweise
Highly poisonous plants of Central Europe (including monkshood, autumn crocus, laburnum, yew, deadly nightshade); what to do if poisoning is suspected
Gesundheitsportal Österreich (gesundheit.gv.at), Bundesministerium für Soziales, Gesundheit, Pflege und Konsumentenschutz: Vergiftungsinformationszentrale (VIZ)
Poison information line in Austria (VIZ), available around the clock; in acute danger 112 or 144
European Parliament and Council of the European Union (2014): Regulation (EU) No 1143/2014 on the prevention and management of the introduction and spread of invasive alien species
EU legal framework for invasive alien species (Union list, which includes giant hogweed)
Headquarters, Department of the Army (USA) (2002): FM 3-05.70 Survival
Avoid poisonous plants; only eat plants after reliable identification
European Resuscitation Council – Resuscitation (journal) (2021): European Resuscitation Council Guidelines 2021: First Aid
First aid for poisoning: call for help, do not induce vomiting