Poison Hemlock (Conium Maculatum) Identification

Poison Hemlock / Spring / Summer / Deadly


Poison Hemlock is one the most deadly plants found growing in the UK and if you forage for anything at all you should definitely invest time in learning how to safely identify this one. It can grow in quite staggering numbers when it gets a foothold and I’ve even seen it growin intertwined with it’s edible lookalike – cows parsley

It’s one of the most deadly toxic plants you will come across quite regularly when foraging and as such is one of the first ones I’d advise learning about.

Common names

Poison Hemlock, Hemlock, Poison Parsley

Botanical Names

Conium Maculatum

Known Hazards

The whole plant is deadly toxic

Could be Confused With

Without doing some research and close inspection, poison hemlock could quite easily be confused with   Cow parsley, or any other of the parsleys. The leaf structure and look of the flowers is almost identical. However there are some key differences. Poison hemlock has purple blotching over the stems which cow parsley doesn’t have, poison hemlcok also has a round stem, wheras cows parsley has a ridge in it’s leaf stems. The last is that poison hemlcok has a rancid smell compared to the mild parsley smell of cows parsley.

Find our in depth guide to Cows Parsley or Poison Hemlock What’s the Difference?

Range and Distribution

Fairly common throughout UK and Europe, also North Africa and Iran 

Video for Poison Hemlock


Waste ground, damp places, and hedgerows often avoid acid soils and heavy shade. Although I find it in many places I often see it more within the fringes of cities and towns.

Physical Characteristics of Poison Hemlock


The stems are rounded and hollow with no hairs, it has purple spots or blotches that become more obvious as the plant matures.


The leaves are feather-like and grow in opposite pairs with a terminal leaf. The leaves are very similar to Cow Parsley but hemlock leaves are typically darker and more glossy.


The flowers are umbels, meaning the flower stems are like the spokes of an umbrella with the flower clusters at the end, the flowers again are very similar to those of Cow Parsley, with a creamy centre and 5 white unevenly sized petals.


The seeds are 2 semi circles, together they make a rounded and striated ball. This plant smells carbolic and unpleasant. 

Edible Use

This plant is deadly toxic, do not eat. 

Herbal Use

This plant is now not really used as medicine. It has been used as an analgesic, antispasmodic, emetic, galactofuge and sedative, it was also used to treat tumors, epilepsy and whooping cough. 


Hemlock contains deadly alkaloids that affect the nerves that control the lungs, causing nerve paralysis and those who ingest Hemlock die of suffocation.


Some more info on the toxins

Identification is key!

Maybe you'd like to join us for some hands-on Foraging?

Find our Up coming Courses here