Disease & Illness

How To Identify Poison Hemlock, On Heels Of Nevada Outbreak

There has been a poison hemlock outbreak in Nevada. Make sure you know what to look for.

It may have been thousands of years ago, but the plant famous for killing Socrates is still around—and still just as dangerous. While it can always be found throughout the United States, there is currently an outbreak of poison hemlock along the banks of the Truckee River in Nevada, prompting parts of Dorosktar Park in Reno to close.

The plant thrives in areas of moist soil and shade and is among the most potently toxic plants people can encounter. It grows to be 6-10 feet tall with leaves and white flowerheads. While all parts of hemlock are poisonous, the seeds contain the highest concentration of poison. Even after death, the cane of the plant can remain toxic for up to three years.

hemlock photo
Flickr | The Equinest

Eating the plant is the biggest danger, but it is also toxic to the skin and respiratory system. If ingested by people or animals, symptoms appear within 20 minutes to three hours.

Typical symptoms in humans include:

  • Dilation of the pupils
  • Dizziness and trembling
  • Slowing heartbeat
  • Paralysis of the central nervous system
  • Muscle paralysis
  • Death due to respiratory failure

Poison hemlock can be confused with Queen Anne’s lace, as well as other members of the parsley family. So, how can you tell the difference between harmless and potentially deadly? Raven’s Roots Naturalist School offers some tips that could save your life if you were to encounter the plant.

  • Poison hemlock stems are hairless with dark purple spots, while Queen Anne’s lace has hairy stems and no purple.
  • Queen Anne’s lace has three-pronged bracts at the base of the flowers, while poison hemlock does not.
  • The flowers on both plants are white and bloom in an umbrella-shaped pattern, but Queen Anne’s lace flowers are flat on top and usually have a single purplish/red flower at the center. Poison hemlock flowers are more rounded, with no colorful flower.
  • While both have leaves that are fern-like, Queen Anne’s lace’s leaves will have hairs on the undersides. The leaves of poison hemlock are not hairy.


Prepare and Protect also points out that when dying, Queen Anne’s lace will fold up like a bird’s nest, while Hemlock will not fold up, but will turn brown. It’s also important to note the smell—if it smells like a carrot, you’ve got Queen Anne’s lace. If it smells musty, it is possibly hemlock.

For more information on poison hemlock, check out the Poison Garden’s website.

[H/T: Bee Habitat]