How Does Hemlock Kill You?

The hemlock plant, known as poison hemlock, is poisonous.
The hemlock plant, known as poison hemlock, is poisonous.

Disclaimer: This article is only meant to dispense medical knowledge about hemlock and its adverse events, as well as its management. It is strongly recommended not to touch or be in contact with hemlock, and inform the concerned authorities if hemlock grows in your vicinity.

The hemlock plant, known as poison hemlock, is poisonous. Its seeds, flowers, leaves, or fruits contain poisonous alkaloid chemicals. Any part can kill you even after ingesting small amounts. Death occurs due to respiratory failure. The alkaloids slowly poison the nerve-muscle junctions and cause the failure of the breathing muscles. Even touching this plant may cause a skin reaction known as dermatitis (itchy skin rash) in sensitive people. Lack of antidote makes hemlock poisoning more difficult to treat.

The poison hemlock (Conium maculatum L) grows throughout the United States, typically during the spring. It is commonly found at lower elevation areas, such as roadsides, ditches and stream banks, fence lines, and creek beds, as well as on the edges of cultivated fields. It can also invade grazing areas, particularly pastures and meadows. It tends to flourish in areas where moisture is abundant. However, it can also survive in dry sites.

Accidental ingestion and resultant poisoning most often result from mistaking its roots of poison for wild parsnips and leaves for parsley.

Poison hemlock is also known as:

  • Poison parsley
  • Deadly hemlock
  • Spotted hemlock
  • European hemlock
  • California fern
  • Nebraska fern

What are the symptoms of hemlock poisoning?

Ingestion of the hemlock plant can take 30 minutes to a few hours to give rise to the poisoning symptoms. The severity of the symptoms depends on how long the plant is there in your system. The common signs and symptoms include:

What is the treatment of hemlock poisoning?

Hemlock poisoning can lead to serious complications. Seek medical help right away if you have touched or eaten any of the parts of the poisonous plant.

Currently, there is no antidote for hemlock poisoning. Doctors treat the condition depending on the severity of symptoms. Treatment usually includes:


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How can you prevent hemlock poisoning?

Elimination of hemlock plants is a sure way to prevent hemlock poisoning. The following are precautions that you should take:

  • Remove the hemlock plants entirely along with their roots. You can remove it manually or use mowers. Place the removed plants in plastic bags and throw them in the dustbin.
  • Wear long sleeves, gloves, and face masks while handling the plant.
  • Do not cut the hemlock plants; they can resprout or emit fumes.
  • Do not burn the hemlock plants. Inhalation of fumes or their contact with skin can result in poisoning.
  • Spray herbicides on the hemlock plants just after the fall or in the early spring. Repeated applications for a couple of years are more effective. Continue the application until the seed bank has been significantly depleted.

Keep inspecting the area of hemlock plants after you have eliminated them by any of the methods.

Make sure to identify the hemlock plant from other edible plants so that you do not ingest it accidentally and fall prey to its poisoning.

Health Solutions From Our Sponsors

DiTomaso JM, Roncoroni JA, Swain SV, Wright SD. Poison Hemlock. University of California Statewide IPM Program.

Agricultural Research Service. Poison Hemlock (Conium maculatum). U.S. Department of Agriculture.