Identifying hemlock, deadly plant, by its leaves. Resembles wild and cultivated carrots, parsley, celery and more.

Poison hemlock (Conium maculatum) leaves closely resemble the leaves of several edible plants.
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I want to talk to you about a plant that I HAVEN'T eaten.

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I haven't eaten this plant, because if I had, I wouldn't still be here.

This plant is Conium maculatum, commonly known as Poison Hemlock. (Also: English or European hemlock, carrot fern, Devil's porridge, spotted hemlock, wild hemlock and poison parsley) It should probably be known as deadly hemlock, as it's one of the most dangerous wild plants you can encounter.

I have read that poison hemlock is so toxic, it has poisoned children who used the hollow stems as whistles -- simply the act of putting it to their lips and later licking them.

C. maculatum, and the closely related (and equally deadly) Water Hemlock (Cicuta species) are members of the greater Apiaceae family. The Apiaceae family is the carrot family, and provides us with many of our most important cultivated edibles, including carrots, parsley, parsnips, fennel, dill, coriander/cilantro, anise and celery. Europeans will also know the food plant "Alexanders".

Because the deadly hemlocks are so closely related to many edibles (including wild carrots/queen anne's lace, sweet cicely, cow parsley, and--more distantly, alexanders (Europe only), parsnips and fennel) they closely resemble them as well, and it's essential for any forager to completely familiarize themselves with hemlock BEFORE they attempt to eat any wild plants in the Apiaceae family.

It's a good thing for gardeners to know about this plant, as it can spring up in their garden, and will resemble carrots, parsley and celery.

But this post will help you safely identify and avoid poison hemlock.

Note: this post deals exclusively with the young, pre-flowering plant, when it is most likely to cause confusion with edible plants like carrot and parsley.

Identifying Poison Hemlock (Conium maculatum)

Click to zoom and inspect in detail. 

Deadly poison hemlock has compound leaves, or a leaf made up of many leaf parts. In the leaf above, you might think that each of those segments is an individual leaf. But rather the whole thing together is one leaf. Moreover, each of the leaf parts is, itself made up of more "leaflet" parts.

Click to zoom and inspect in detail. 

Poison hemlock leaves are smooth and hairless. You may want to check with a magnifying glass to confirm.

Click to zoom and inspect in detail. 

Click to zoom and inspect in detail. 

The leaf stems (properly known as petioles) are smooth and hairless. The undersides of the leaves are also hairless.

Click to zoom and inspect in detail. 

Click to zoom and inspect in detail. 

Mature Conium maculatum plants will have purplish-red blotches along the stem, especially near the base.  Important note: young plants may not exhibit this blotching!

Click to zoom and inspect in detail. 

There is nothing distinctive about the look of poison hemlock root, it resembles many edible roots. However, some people describe it having an unpleasant odor. My nose is not so keen, it doesn't smell unpleasant to me.  I don't recommend relying on smell to ID hemlock.

When you aren't sure what you have

If you are not over 100% certain about a plant that even slightly resembles poison hemlock, DO NOT EAT IT. No meal is worth this level of risk.

Instead, take some time to study the plant. Take pictures from multiple angles. Use a magnifier to inspect the details. Pick it (just wash your hands after), smell it (but DON'T taste it), and get a feel for it. Come back later in the year and observe again. Has it flowered? What do the flowers look like? Smell like?

Similar looking, edible wild and cultivated plants*

The below information is NOT enough to identify edible wild plants in the carrot/parsley family. Do not use this for positive identification, rather just for your awareness of what's out there, and how closely it resembles poison hemlock.  
Beginner and novice foragers should not eat from the carrot/parsley family.  
With the carrot family, you must have identification down to a species level before consumption. DO NOT rely on genus identification and especially not on common names. 

Wild & cultivated carrots, parsleys, chervil, sweet cicely and cultivated celery 
I'm sure you've heard by now that many members of the carrot/parsley family (Apiaceae) resemble poison hemlock. Like hemlock, these plants have frond-like, compound leaves. Part of the confusion is that many of the images on the internet are mis-identified, with plants being labeled "carrot" that are actually poison hemlock, cow parsley, or hedge parsley, and vice versa.

While this is not a comprehensive list for identification, it will give you some quick tips on how to distinquish these plants from poison hemlock, should you encounter them on a forage or in your garden.

• Wild and cultivated carrots. Daucus carota and subspecies: hairs on the stem and the undersides of the leaves. These hairs are tiny, and older eyes may want to confirm with a magnifying glass, but they must be there to help distinguish from poison hemlock. All cultivated carrots are subspecies of the wild carrot, Daucus carota, and so they share most features. 



Hedge parsley leaf. This image has been magnified to
show the leaf hairs. Click to enlarge.

• Wild parsleys, including hedge parsley (Torilis arvensis and Torilis japonica) and cow parsley/wild chervil (Anthriscus sylvestris): look again, for hairs. For hedge parsleys, the stems and leaflets will have tiny, upright hairs. These hairs are generally not visible to the eye (unless you have very good vision), but will require magnification to confirm. Cow parsley/wild chervil lacks the hairs on the leaves, but will have hairs on the leaf stalks and main plant stem. Again, you may require magnification. 
• Cultivated flat-leaf parsley (Petroselinum crispum variety neapolitanum): 
• There are many other species of "wild chervil". At least one of which, Chaerophyllum temulum, is poisonous.
• Sweet cicely (Osmorhiza claytonii): look for long hairs on the stem and leaf stems. 
• Celery (Apium graveolens): 

Alexanders and wild and cultivated parsnips
The leaf shapes of alexanders (Smyrnium olusatrum), and parsnips (Pastinaca sativa), don't closely resemble that of poison hemlock, at least not to me.

However, they do somewhat resemble the equally poisonous water hemlocks, Cicuta douglasii and Cicuta virosa.

If you are harvesting Alexanders (which is a Europe-only plant), or parsnips, and you are concerned about look-a-like species, make sure to investigate Cicuta species.


*As always you should never accept anything you read on the internet without verifying it for yourself with either a local expert or several publications. Colors can vary from monitor to monitor, and images are not as clear as in printed materials. And again, this entire post is not designed to help you ID an edible member of the carrot family, but to help you ID a deadly poisonous one. Do not eat anything based solely on the information on this page. I may decide to later go back and create ID posts for some of these edibles.