Hemlock Water Dropwort

Poisonous Poisonous Spring Spring Summer Summer Winter Winter

The most poisonous plant in the UK and very common along most of our waterways.

Hedgerow Type
Common Names Hemlock Water Dropwort, Water Hemlock, Dead Mans Fingers, Dead Tongue
Scientific Name Oenanthe crocata
Season Start Feb
Season End Jul
Please note that each and every hedgerow item you come across may vary in appearance to these photos.


Bright green and shiney, a bit fern like with two to four pinnate divisions, the whole looking triangular in shape.


A collection of small white flowers arranged in an umbel.


Small brown rugby ball shaped seeds in clusters replacing the flowers.


Bright green, hollow, grooved, hairless, shiney and up to six feet tall. When cut the stem exudes a staining yellow liquid.


Damp areas including marshes, lake, river and stream sides or along ditches. Can be found several meters inland from water sources.

Possible Confusion

Flat leaved parsley, water parsnip or water celery.


Like very sweet parsley, its lovely smell gives no indication off how toxic this plant really is.


The root is said to taste pleasantly like parsnip before poisoning the consumer.


Very common along waterways, damp ditches and marshy areas.

Medicinal Uses

Being the most poisonous plant in the UK, this is not used for medicinal purposes.

Other Facts

The term sardonic grin comes from the grisley practice in Phoenician Sardinia of disposing of criminals and old people using Hemlock Water Dropwort. The poison acts by constricting the muscles causing death by asphixia which also causes a rictus like death grin, the sardonic grin.
Hemlock Water Dropwort is the most poisonous plant in the UK and all parts of it are poisonous, it is reported that death can occur in as little as a couple of hours after ingestion.
Hemlock Water Dropwort is in the Apiaceae family, one of great interest to foragers as the family contains many fine edibles and a good handful of deadly poisonous species.


24 comments for Hemlock Water Dropwort

  1. Patty Inman says:

    Hi, how do i book onto a foraging workshop? When is the next cheshire days on? Im from Liverpool area so im supposing cheshire is nearest?
    Thank you
    Bright blessings
    Patty xxx

    1. Poppy Ives says:

      Hi Patty, yes Cheshire is our nearest venue. Our spring courses there are fully booked but we have available spaces on our summer courses on 14th June, 19th July and 3rd August.
      You can book them online here https://www.wildfooduk.com/foraging-trips/cheshire-marbury-country-park-summer-foraging-courses/

  2. Linda Schofield says:

    I have been offered a site for an out apiary for my bees. I am aware that there is water drop wort on the site, as some grazing cattle had died there after eating it (about 30 years ago). As the plant is umbelliferous, it is likely to attract the attention of my honey bee foragers. Would there be any risk from eating honey from this source?

    1. Eric Biggane says:

      Hi Linda, it’s rare for a plant to produce poisonous nectar as it would affect the bees. I can’t find anything specific to Hemlock Waterdrop Wort but I did find an article stating that the poisonous Hemlocks don’t produce poisonous nectar. http://www.quora.com/If-a-bee-pollinates-a-poisonous-plant-such-as-hemlock-or-oleander-and-the-honey-is-harvested-from-this-particular-population-could-it-harm-the-humans-who-eat-it-On-the-same-note-what-if-you-are-stung-by-that-bee

  3. Barbara Jones says:

    I’ve seen speculation that the genes that make cilantro (coriander leaves) taste bad (like soap or stinkbugs) may have evolved to help people evade plants like this one, and that these genes may have originated where this plant lives. Has anyone heard about this theory?

  4. Cai Williams says:

    There are loads of these growing in my garden near where the stream is. I’m rather worried about this. Is it possible to get rid of them safely?

    1. Eric Biggane says:

      They will be hard to dispose of, really good for wildlife and are only poisonous if you decide to eat some.

  5. John Phillips says:

    Hi. I suspect that this plant is abundant at Farlington marshes near Portsmouth. It is growing in boggy ground and ditch edges. It is coming into full flower at the moment. Should the Wildlife Trust put up warning notices?

    1. Eric Biggane says:

      Hemlock Water Dropwort grows along nearly all the waterways I know so they would have to have warnings everywhere. There are a lot of poisonous plants out there, hopefully people will only attempt eating things they are 100% sure of the identity.

  6. Frederick says:

    Will I run in to any problems from having touch and picked one or two of the leaves – or is only toxic on ingestion

    1. Eric Biggane says:

      Touching Hemlock Water Dropwort will not cause any problems it is only ingestion that can harm you although after touching it one should wash their hands before eating anything else.

    2. Lucie swan says:

      I’ve got a paddock with my ponies on. I discovered hemlock water dropwort on the edge of it.
      What would be the best way of getting rid of the plants so my ponies don’t eat it.

      1. Eric Biggane says:

        Horses are usually able to distinguish between poisonous and edible plants but will eat the wrong plants if there is nothing else about to eat. You can dig the plant and roots out, this should get rid of it but dispose of the plant carefully, especially the roots as they are the most toxic part. It is safe to touch the plant but while digging it out I would wear gloves just to be extra safe.

  7. Mrs C Hankinson says:

    I am fairly sure we have a huge amount Hemlock Water Dropwort around and in the stream in our garden and by the stream in our field where we graze both sheep and horses. NFU won’t help as I do not have a membership number. Natural England won’t advise. Gov.Uk Environment agency won’t advise. Defra havn’t answered their phone for 3 days. Dorset Council referred me back to Natural England. Some of these won’t advise because it is not included in their lists!
    Any idea how I can get rid of it without leaving tiny traces (which would still be deadly), which the animals might unknowlingly eat and die. Poisoning isn’t an option in most areas as it is growing beside the water.
    Would really appreciate some help

    1. Eric Biggane says:

      Livestock will only eat hemlock or hemlock water dropwort as a last resort if there is no other available food source, cases occur in years of drought when the grass and other weeds have died back. Cutting it down or digging it up before it flowers will help and there will be less every year but it is a very common plant and will spread from upstream. I know how to avoid the plant but I’m afraid I’m not an expert on getting rid of it.

  8. Dodgy Dave says:

    I thought this huge crop covering a dry stream bed was Wild Celery after looking it up and tried some leaf and stalk. It did not taste nice , nothing like celery. My dear sister had kittens when she scanned it with her identification phone app.
    I was lucky. Do not try anything unless you are 300% sure what it is.

    Dodgy Dave

  9. Richard Bond says:

    You need to dig it up. Wear gloves. First chop the heads off so the seeds don’t spread if it’s reached that stage. Then pull up the stalks with root if possible The tap root may go quite deep but try and dig that up if the stalk breaks. In soft ground by a stream should come up easily. If you have cattle I’d fence it off while you clear it. It’s an on going thing every year. You should burn it so the seeds don’t get passed on.

  10. Robert French says:

    ……what wild life benefits from the Hemlock Water Dropwort ?

    1. Eric Biggane says:

      The marsh fritillary butterfly, hoverflies and flower, longhorn and soldier beetles are all fond of hemlock water dropwort and along with midges, mosquitos and a host of other insects, help pollination.

  11. Susan says:

    Do you do any courses in Hampshire?

    1. Eric Biggane says:

      We have courses running in Queen Elizabeth Country Park and hoping to get conformation for running courses in the New Forest. Many courses are fully booked at the moment but that is because we have kept the numbers down due to possible covid restrictions. As lockdown eases we hope to up the numbers so will have more spaces nearer to the course dates.

  12. Northern Summer says:

    Noted some clips from US show Poison Water Hemlock as having leaves similar to Ground Elder which is puzzling me. Any thoughts please?

    1. Eric Biggane says:

      We don’t have Poison Water Hemlock, Cicuta virosa, in the UK, we have Hemlock Water Dropwort, Oenanthe crocata, which has fern or parsley like leaves, unlike the leaves of Poison Water Hemlock which are similar to ground elder.

  13. Kieran says:

    U can’t eradicate a plant because some moron might eat it by mistake surely that is the kind of actions we have learned from our mistakes in the past lol 😂🤣

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