I have always admired the wild native Queen Anne’s Lace, Daucus carota. It is such a pretty, white flowered roadside plant more often thought of as a weed. A member of the carrot family Apiceae, it is a rather benign plant. However, it has really a nasty cousin, Poison Hemlock that resembles Queen Anne’s Lace, can be mistaken for it, and that is not something to do.
In addition to Queen Anne's Lace, wild parsnip, spotted water hemlock, and purple-stemmed angelica sometimes can be confused with poison hemlock because they are in the same family and have some similar features. Cow parsnip and giant hogweed are also in the same family; however, they are much larger in stature and also should be avoided.
The word hemlock brings to mind poison for good reason. Poison Hemlock is most often connected to the Greek philosopher Socrates, who in 399 BC, was executed by being ordered to drink poison hemlock after he was convicted in a one-day trial for "impiety", which is lack of piety or reverence for a god. A very interesting philosopher, Socrates actually embraced his own death.
Botanically known as Conium masculatum, Poison Hemlock has both very similar lacey white flowers and fern-like foliage. It is a biennial with the first year’s foliage looking much like [parsley. Second year’s flowers look very much like Queen Anne’s Lace, only the mature plant can be much taller by several feet, up to as much as six feet, and the flowers are umbrella shaped clusters not quite as flat in appearance as Queen Anne’s Lace. A key identifier in addition to the mature height is the stems are not hairy, and are marked with distinctive maroon or purple blotches.
Poison Hemlock grows in full sun to part shade and moist soils. It produces seeds that are spread by animals and can persist in the soil for years making eradication difficult. The roots, leaves and stems have a bad odor if crushed, however, just avoid this plant. Exposure to the skin can cause irritation. Even dead or dried plant materials contain the toxins for years.
One does not want to make contact with Poison Hemlock.
Poison Hemlock is acutely toxic to humans and animals such as horses, cattle and other livestock. While ingestion is the main cause of fatality, toxins are found in all parts of the plant’s tissues and cause serious skin irritation. Symptoms can appear from twenty minutes to three hours after ingestion, and can lead to death by respiratory paralysis. Quick treatment can reverse the harm, and typically there are no noticeable aftereffects. If suspected poisoning from this plant, call for help immediately because the toxins are fast acting for humans, call 911 or poison-control at 1-800-222-1222 or for animals, call a veterinarian.
If found, how to control Poison Hemlock - Use caution and protect skin from exposure by wearing gloves, long sleeves and long pants during any eradication attempts. Small amounts can be dug taking care to remove the taproot. Bag and dispose of materials in the trash. Prevent seed production. Chemical herbicide applications in spring and fall are more effective for eradication. Always follow herbicide label instructions.
Another very nasty hemlock cousin and member of the carrot family is the much more toxic Water Hemlock, Water hemlock is a wetland plant found growing in wet seepage areas of pastures, meadows and streams geographically in the western states. Plants usually grow in small patches and are easy to locate.
Water Hemlock is considered "the most violently toxic plant that grows in North America". It contains cicutoxin that has a strong carrot like odor and acts on the central nervous system differently from Poison Hemlock, but just as deadly if not more so since it acts much more quickly. Infected animals can seldom be saved. It also has small white umbrella like flowers that grow in clusters. It has thick rootstalks containing small chambers of the toxin in a liquid form that is released if the stem is broken such as in being eaten by cattle. The underground parts of the plant also are highly toxic. Herbicide treatment is effective and all dead plant material must be removed due to residual toxicity.
Because of its attractive flowers, Poison Hemlock was brought to the US from Europe as a garden plant. It has moved into the environment and is found along roadsides and cultivated lands. Consider the potential poison hazard if encountered.
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