Poison Hemlock Alert

Like the latest meme, Poison Hemlock (Conium maculatum) seems to be having a moment in and around South Orange. Green Teamers have noticed this dangerous and toxic plant in various locations along the river and even in the community garden!
This is concerning because all parts of the plant are toxic and dangerous to humans, pets, and livestock. The sap alone can cause skin irritation for some people and the leaves, flowers, seeds, and roots are all poisonous if ingested. Significant ingestion can result in muscle paralysis, suffocation, and even death. By Learning to identify, avoid, and/or control this plant you can avoid a nasty rash or worse.


Why would I eat this? Good question, and the short answer is mistaken identity.

Poison Hemlock is in the carrot family so the leaves, foliage, and root share many features with carrot, parsley, Queen Anne’s lace (wild carrot), wild parsnip, spotted water hemlock, and purple-stemmed angelica.

Being in the carrot and parsley family means that the foliage has a fernlike pattern that may look familiar. The flowers are white, umbrella shaped flower clusters each having five petals. The plants can grow to as much as 10 feet tall. The most distinguishing feature is the red or purple spotting or streaking on the stems, especially closer to the base of the plant.  


Poison hemlock is non-native to North America and that means it doesn’t have native competition or predators to help control it. When hemlock flowers, each plant can produce as many as 30,000 seeds, that birds (which are not sickened by it) gobble and spread to new locations.

If you happen to identify this plant on someone else’s property, contact the property owner about removal. If you find it on your property, do not mow or weed-whack it with a string trimmer as this can splatter sap and seeds. Instead, wear protective gloves, mask, and eye protection and remove the entire plant including the roots. Do not compost it; bag it and put it in the trash. You may also be able to find professional removal services locally.

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