A CASE OF MISTAKEN IDENTITY

Poison Hemlock (Conium maculatum) (Source)

Digger Spade, MG Plant Detective

The client called with a straightforward question.  How to identify Poison Hemlock?  The answer is quite easy to find, the internet comes up with 259,000+/- sites that have some relevance to the question and the first hundred or so deal with identifying the plant.  Among the plants that look somewhat similar it differs in having purplish blotches on its stems and a slightly different leaf structure.

I asked the client if he wanted to get rid of some.  His answer was quite a surprise, he said “No, I ate some, I thought  it was wild carrot.”  Fortunately unlike Socrates he hadn’t taken a fatal dose having put his find into a soup which would have diluted the concentration.  I asked how it tasted.  Not great. And he did end up in the emergency room.

Well there is a wild carrot, it is called Queen Anne’s Lace (Daucus carota) (1).  It is the same species as the ones we eat though a different subspecies.  It is a problem to carrot seed growers because it can hybridize with commercial varieties.  The foliage is irritating to some but is  reported to be edible, as are carrot greens.  To tell the edible from the poisonous the client probably should know more about poison hemlock than that it has purple blotches.  We got his e-mail address and sent him the links below.  Our conversation ended with the client assuring me that his days of wild carrot consumption were over.

Though Queen Anne’s Lace is reported to be edible very few of the sites that promote eating from the wild list it.  And the root doesn’t seem to be the part that is eaten though it was brought from Europe as an edible and decorative plant.  As with quite a few other introductions it has escaped and is a noxious weed with some indications of toxicity to cattle.  The best thing to do with it is kill it, not by eating it.

There are other plants that resemble Poison Hemlock (Conium maculatum) (2) to some degree.  And some are health hazards too.  They are all in the Apiaceae family but in different  branches of it.The worst is Water Hemlock (Cicuta douglasii) (3) a wetland plant with distinctive hollows and color in its roots that also smell strongly of carrot.  The most poisonous plant on the continent! according to the USDA.

Then there is Cow Parsnip (Heracleum maximum) (4) a native species that looks like Giant Hogweed (Heracleum mantegazzianum) (5) a noxious weed of spectacular size and a high priority for elimination.  Giant Hogweed can have flower stems to 15 feet while Cow Parsnip only gets up to 8 feet or so.  Both exude sap if damaged that is phototoxic and causes large blisters on exposed parts. So telling them apart isn’t important from a health point of view but it is for being a good steward and getting rid of the big one.  Cow Parsnip is reported to be eligible and tasty but Giant Hogweed is reported to be inedible.  If you want to eat wild be sure you know whereof you are partaking; once you have identified the plant the FDA  provides a search of toxicity information (5).

This odd case seemed worth reporting because Poison Hemlock, Giant Hogweed, Queen Anne’s Lace, Water Parsnip and Cow Parsnip are fairly common, look a lot alike and often need to be eradicated.  That should be done with caution and full body coverage.  I can attest that wearing shorts while whacking cow parsnip on a sunny day will be regretted at leisure.


1. Queen Anne's Lace, Daucus carota (OSU)
https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/pnw447.pdf

2. Poison Hemlock, Conium maculatum (King County)
http://www.kingcounty.gov/environment/animals-and-plants/noxious-weeds/weed-identification/poison-hemlock.aspx


3. Water Hemlock, Cicuta douglasii (WSU)
https://research.wsulibs.wsu.edu/xmlui/bitstream/handle/2376/4837/PNW109.pdf?sequence=2&isAllowed=y

4. Cow Parsnip, Heracleum maximum (WSU)
http://extension.usu.edu/rangeplants/htm/cow-parsnip

5. Giant Hogweed, Heracleum mantegazzianum (WSU)
http://hortsense.cahnrs.wsu.edu/Public/FactsheetWebPrint.aspx?ProblemId=2068