Extension office warns of poisonous plants

Submitted by Dr. Don Deever
University of Nevada, Reno Extension

Deadly poisonous plants exist in the county in no short supply, and during the spring bloom and burst of green that presently surrounds the citizens of Lincoln County with welcome relief from winter, many of the most toxic wild herbs look as tempting to eat as the fruit from the Biblical “Tree of Life.” However, to the uninformed at this time of year, the result might be the opposite of life, as the following report demonstrates. 

It’s helpful to know that the University of Nevada, Reno Extension office in Lincoln County exists to provide many services to the county, including bringing university-backed knowledge directly to the homes of people who need it most.  One service that some specially-trained Extension educators can provide is the identification of poisonous plants in one’s lawn or garden. Accordingly, on Wednesday, May 6, while identifying the weeds that were growing in a garden area in Castleton, in a spot that had previously been planted with carrots, a patch of poison hemlock (Conium maculatum) was found to be thriving. It is interesting to note that this is the genus of plant that was given to the ancient Greek philosopher Socrates, as ordered in his execution, and history shows that the prescribed hemlock carried out his death sentence without delay.

The purpose of this news release is to let the public know that if they have any wild plants that they “think” might be an edible vegetable that has escaped cultivation, they should never try anything without being 100% certain of the species they are dealing with. While there’s a popular English idiom which states, “The road to [you know where] is paved with good intentions,” it is equally apt to say that the same road is paved with false assumptions. In the case of poison hemlock, it’s a road that offenders seldom have a second chance to travel.

Poison hemlock is not uncommon in the county this time of year, and it is a beautiful looking plant. In fact, as fate would have it, just a short while after looking at the poisonous weeds in Castleton, Providence decreed that the Extension Educator would fill his truck up with gas at a Pioche station that is immediately adjacent to the world famous “Million Dollar Courthouse.” Seeing fragrant lilac in bloom that was growing against the historic building, the Extension Educator walked over to take a photograph. When he did, he saw that all around the front of the courthouse was a profusion of mature poison hemlock plants where tourists tread.

The big problem with poison hemlock, which results in numerous deaths around the country each year, rests in the fact that the plant looks imminently edible. In fact, it is related to parsley, carrots, and parsnips, but its luxuriant foliage looks greener, shinier, and more enticing than the crops that are its cousins. For this reason, many victims of poison hemlock have inadvertently added a leaf to a sandwich, or pulled the plant up to find a white taproot, which they mistook for a pale carrot or tender parsnip. Unfortunately, it’s not a mistake that most victims get to make twice.

Poison hemlock is considered to be in the “top ten” most poisonous plants on Earth, sharing that infamy with the likes of castor beans (source of the deadly poison ‘ricin’), oleander, wolfsbane, and angel’s trumpet, to name a few. The fatal ingredient in poison hemlock is a toxic alkaloid known as coniine that works as a potent neurotoxin, which results in a condition known as “ascending paralysis.” In other words, the toxin begins to paralyze muscles, starting with the legs, and then works its way up to a person’s respiratory muscles, which commonly results in death by oxygen starvation. If treated in time, victims can be kept alive through artificial ventilation, but it can take 48 to 72 hours for the poison to work itself out of one’s system. Moreover, it only requires the ingestion of 1/10^th of a gram of coniine to produce fatal results.

There is no edible part of this weed, and unlike the order in which the plant produces it dire symptoms, it becomes increasingly toxic the deeper down one digs, until reaching the roots, where a majority of the toxin is concentrated. Later in its growing season, toxic coniine also becomes highly concentrated in its seeds. When eradicating the plant from one’s yard, homeowners and other gardeners should avoid touching the plant with their bare hands, since the juice is also highly toxic. Therefore, it is recommended that the plant be removed with a shovel and only handled with rubber gloves, and that those gloves should be properly disposed of afterwards. To be on the safe side, neither the plant nor the gloves should be burned. Some reports have shown that poison hemlock toxicity is great enough to kill a grazing cow in 15 minutes.

When in doubt about any suspected plant in one’s garden, know that you can take a photo of that plant with your smartphone or other camera, and send that photo to the Extension office for proper identification. It’s better to be safe than to leave your family sorry, especially with a plant whose theme song could be, “Nearer My God to Thee.”

To contact the Extension office in Lincoln County with questions and/or photos about any suspicious plant growing in your garden or yard, email Extension Educator Don Deever at ddeever@unr.edu.