Poison Hemlock

Conium maculatum

It's hard to choose what adjective best describes poison hemlock, but "big" is certainly a contender.  It looks a little bit like common Queen-Anne's-lace on steroids.  Like Queen-Anne's-lace it is a biennial, living two years.  The first year it produces a low rosette of leaves; the second year it takes off, growing into a huge, flower-covered plant up to 9 feet tall.  "Pretty" is another adjective that comes to mind.  The plant itself is too big and coarse to be considered pretty, but the tiny white flowers, with their five petals are elegant and are born in profusion in flat topped-clusters known as umbels.  The leaves are finely divided and fern-like.  The stems, which are hollow, are mottled with purple, as seen in the picture below. 

Poison hemlock is a weed.  A simple definition of weed is a plant found where humans don't want it.  A lovely petunia in the lettuce bed, for example, is a weed.  To botanists the term weed has a more particular meaning.  A weedy plant to them is one that can thrive in disturbed areas.  Living in disturbed areas is a perfectly respectable evolutionary adaptations.  Nature creates disturbed areas frequently, whenever a major storm knocks down trees, or lightning sparks a fire.  These provide opportunity for early colonizing species that like open space, lots of light, and disturbance.  Mankind, too, creates lots of disturbances.  Roadsides, trailsides, backyards, and agricultural fields are all disturbed areas.  Plants that like disturbance found humans a blessing and multiplied in villages and on roadsides.

And they spread with us.  Stuck to our clothes, wedged into cracks and crannies of our wagons and trains, sealed in clumps of dirt in the tread of our car wheels, their seeds went everywhere we went.  Even oceans were no barrier to them; they crossed over sealed in bales of hay taken aboard ships to feed cattle bound to overseas colonies.  Most of the more familiar wildflowers in the eastern United States, dandelions, daisies, clovers, sweet clovers, wild sweet peas, are all weeds that came from Europe.  Botanists call weeds that have traveled outside their natural range by hitching rides with humans, alien or exotic weeds.

Poison hemlock is one of them.  It is originally a native of Eurasia, but has spread well outside that range.  In North America it is now found from Quebec to Florida westward to the Pacific coast.  It can be found mostly in waste places, and along roadsides and bikeways.  In Wildwood it can be found along the Riverway.

All parts of poison hemlock are deadly poisonous.  Even blowing into whistles made from the hollow stems has caused poisoning, although touching or brushing against the plant is not dangerous.  The plant contains an alkaloid, coniine, that causes paralysis, leading to suffocation and death.  In ancient Greece, extracts of the plant were used to execute criminals; Socrates is perhaps the most famous victim of this practice.  Surprisingly the plant has been used medicinally, in very low doses, as a sedative, but this would seem rather unwise.  Alkaloids are nitrogen-containing compounds that plants make, presumably to poison insects and other creatures inclined to munch on them.  Many alkaloids are deadly poisons, such as nicotine and strychnine, and, of course, coniine.  Others have been used by humans to cause mild, pleasurable self-poisonings, caffeine and theophylline (in tea) are examples.

The genus name Conium comes from the Greek name for the plant, koneion.  The common name comes from the Middle English name for the plant.  The species name maculatum, means "spotted" and refers to the purple spots on the stem.

Poison hemlock is in the Apiaceae, or Celery Family.  This is a large family, of about 3000 species worldwide, but mostly in the drier temperate regions.  Members of this family are characterized by having their flowers in flat-topped clusters or umbels; in fact, an older name for the family is Umbelliferae, which means "umbel-forming."  Most members of the family also have leaves that are divided up into segments, sometimes intricately so, as we see here for poison hemlock.  Hollow stems is another character of most members of the family.