Poison Hemlock
A couple of weeks ago a friend sent me a link to a newspaper report about an unfortunate individual in Ohio who, to make a long story short, ended-up in the hospital on a ventilator from doing yard work. As of June 14, he had been unable to breathe on his own and had been on a ventilator for 41 days. No COVID-19 involved in his inability to breathe, just pulling-up weeds that around the yard.
The culprit was an invasive alien that is very common here in Carroll County, Poison Hemlock (Conium maculatum). Every year there are cases of poisoning from people mistaking the plant for wild carrot and eating the root, with unpleasant, sometimes fatal consequences. This was the first time, however, that I had heard of somebody ending up in the hospital from pulling up a weed. When I looked into it further, it made perfect sense.
Here in Carroll County this prolific roadside weed can get to six to ten feet tall. It has luxurious fern-like leaves when it begins its growth in spring, but then shoots up a tall stalk which has telltale purple blotches, hence the species name “maculatum” which means spotted.
The tiny white flowers are in flat-topped, umbrella-like clusters, just like wild carrot. Now it’s about done flowering and is producing seed. Of all plant parts, the seeds have the highest amount of the toxic alkaloid, coniine, which is a volatile alkaloid. All parts of the plant contain coniine in varying degrees, so if you were pulling up the plant, or many of them, you could easily expose yourself to enough of this toxic compound either by breathing it in as it volatilizes or perhaps absorb it through the skin if you bruised and crushed the fresh vegetation.
The name Conium derives from the Greek konos or “cone top” referring to the hats worn by Sufi whirling dervishes, alluding to the plant’s toxic effects. Soon after coming in contact with the coniine-laden juice of the green plant, dizziness with a spinning sensation foretells impending doom. Ingested purposefully or by accident, the victim will not be able to stand-up or sit. One must lie down. Muscle function ceases. The victim who remains alert and conscious ‘til the end has 30 minutes before lungs and heart fail to function.
It was the mode of execution by the tribunal of Areopagus, famously administered to the philosopher Socrates, 470-399 BCE, whose crime of not believing in the city’s gods and expressing that to others, earned him a death sentence.
And that’s why it’s good to know a little basic plant i.d.