Wednesday, May 4, 2011

Lethal Carrot

Queen Anne's Lace- Wikimedia
Carrots are generally considered good for you.  The carrots we eat are cultivars of wild carrot Daucus carota (a.k.a. Queen Anne's Lace).  However there is a black sheep in the dark corners of the Apiaceae i.e. carrot family --- Poison Hemlock.
Early leaves in April

May is the time that the flat mats of Poison Hemlock bolt, rapidly shooting up to their mature height of 5-8 feet.  This growth before other plants have their wits about them ensures that sunlight won't reach the neighbors.  They hang on through the summer, their stems developing purple blotches.

Poison Hemlock (Conium maculatum) is a native of Europe, Central Asia and North Africa.  It is a member of the carrot family, with foliage reminiscent of also non-native Wild Carrot (a.k.a. Queen Anne's Lace).  There the resemblance ends as Hemlock has ridged stems with purple spots and smooth leaves.  There are good pictures at missouriplants.com.

Poison Hemlock was the drug of choice for execution in Greece, made famous by the description of Socrates' death.  It contains coniine, a toxic alkaloid similar to curare, which blocks neuromuscular transmission, leading to progressive muscular paralysis over minutes to hours and eventually death by suffocation.  If only Socrates had CPR by a kind soul and a ventilator, history would have been changed.

Poison Hemlock Root
The dramatic description of Socrates' execution perfectly describes the ascending paralysis.  The same effect is produced in livestock.  Cattle eating 1-2 pounds or sheep with less than a half a pound will suffer the same effects.  Whistles made from hollow
stems of poison-hemlock have even caused death in children.  USDA

For those of us without livestock, this invasive plant can take over a pasture or disturbed soil in several years, shading out all the native vegetation before they get a start.  Missouri University has good information on controlling poison hemlock.