Conium maculatum, commonly known as hemlock,
is a biennial herbaceous plant belonging to the Apiaceae family (the
same family as carrots and parsley) which is notable for being highly
toxic and lethal to both humans and animals. It is famous in history
because its poison caused the death of the Greek philosopher Socrates.
It is often mistaken for similar-looking edible plants, such as parsley
or wild carrot. To distinguish it, one must look for three key features:
Purple spots on the stem: Its stem is erect, hollow and smooth, and is
typically covered with purple or reddish spots or speckles. Bright
green, triangular and deeply lobed leaves (resembling a fern). When
rubbed, they give off an unpleasant, foul odour, similar to mouse urine.
Flowers grouped in umbels (small, umbrella-shaped clusters) consisting
of a multitude of very small white flowers. It can grow to a
considerable size in its second year, reaching a height of between 1.5
and 3 metres. It is native to Europe, North Africa and temperate
Asia, although it has become naturalised and been introduced to many
regions of the world (such as North America), where it often behaves as
a highly aggressive invasive species. It usually grows spontaneously on
roadsides, wasteland, rubbish tips, riverbanks and wet areas with
nitrogen-rich soils. All parts of the plant — from the root to the
seeds and flowers — contain neurotoxic alkaloids, the main one being
coniine. It blocks the peripheral nervous system and the
neuromuscular junction in a similar way to curare. The main clinical
symptom is ascending muscle paralysis. It begins in the legs and
progresses to affect the respiratory muscles, leading to death by
asphyxiation or respiratory arrest whilst the person remains conscious.
Even a minimal amount of fresh leaves or seeds is sufficient to cause a
fatal outcome.
El Hierro, La Palma, La Gomera, Tenerife, Gran
Canaria