Tag Archives: cuckoo bumblebees

A chance encounter with monkshood, our most poisonous plant

It had been a good week but very intense.  Our exhibition, entitled Observation, had come to an end and the combination of Hazel’s paintings and my photographs brought many interested people into the gallery leading to good conversations. When the exhibition finished, just over a week ago, we were both tired and needed to recharge.  So, on the Sunday after, with the weather looking good, we set out on a walk in the countryside.  Part of our route took in a quiet riverside path with meadows along one side spreading up the gentle slope away from the river.  Buttercups and catsear lent the meadow a midsummer look and beneath the nodding yellow flowers were lush grasses, globes of white clover, a few pink orchids and some good stands of yellow rattle with its hooded lemony flowers and black beaks.  It was a fine meadow with plenty of insect life and we watched the many bumblebees feeding,  clover being their favourite.  We saw several cuckoo bumblebees which, as their name suggests, don’t make their own nests but parasitise those bumblebees that do make nests.

the riverside meadow

On the other side of the path, there was a band of trees, scrub and other vegetation bordering the river and among the shady greenery we noticed a tall plant with a skein of dark purplish-blue flowers (see picture at the top of this post) that reminded me of Dutch clogs.  Neither of us had seen this plant before and, with its showy blue flowers, we speculated that it might have been a garden escapee.  More of the unusual flowers appeared further along, in the same sort of environment, under shade and close to the river.

More monkshood growing by a path under the riverside trees (photo by Hazel Strange)

Back home I wanted to find out what this plant was and eventually I discovered that it was Aconitum napellus or monkshood.  In the south west of the UK, where I live, some rare examples of monkshood may be native but most are introduced and naturalised.  The unusual architectural look of the flowers has made it a popular garden plant and the name, monkshood, derives from the resemblance of the flowers to the hoods or cowls worn by monks in the past.

What surprised me most was the warning in my flower book that monkshood is the most poisonous plant found in the UK.  All parts of the plant are highly poisonous, containing the substance aconitine, an alkaloid that causes death by disrupting the ionic balance across cell membranes leading to respiratory and heart failure.  The dangers of monkshood have been known and exploited since ancient times resulting in the name “Queen of poisons”.  Extracts of the plant were applied to spears and arrows to increase their killing ability and the poison was used in ancient Rome for executions.  The plant is sometimes called wolfsbane owing to its use for killing wolves and its reputed ability to repel werewolves, but the name is more usually applied to the related, yellow-flowered, Aconitum lycoctonum.

Preparations of aconitine have also been used, mostly in the past, for their medicinal properties in treating pain and fever when taken orally or as a liniment for treating rheumatism, neuralgia and sciatica.  Tinctures of aconitine were freely available in 19th century pharmacies in Europe and the US but although the drug is no longer used in conventional medicine in the west, it continues to be used in India and China in traditional herbal preparations. The problem with using the drug is balancing the apparent therapeutic effects against the lethal effects and cases of accidental aconitine poisoning are not unknown in China.

Cerberus with Hercules (Detail from a Caeretan black-figure clay vase from Cervetri (Caere), about 530 BC. Paris, Musée du Louvre E701. © Photo: Max Hirmer Licence Plate 11 UK 1007 127)

The plant is said to have arisen, according to Greek mythology, when Hercules, performing his 12th labour, dragged the three-headed dog Cerberus from the Gates of Hell.  Here is Ovid’s description in his Metamorphoses:

“The dog struggled, twisting its head away from the daylight and the shining sun. Mad with rage, it filled the air with its triple barking, and sprinkled the green fields with flecks of white foam. These flecks are thought to have taken root and, finding nourishment in the rich and fertile soil, acquired harmful properties. Since they flourish on hard rock, the country folk call them aconites, rock-flowers.”

It seems entirely appropriate that such a lethally poisonous plant should be associated with the Gates of Hell. Indeed, it might be expected that a plant with such a reputation would have been used to commit murder but there are very few contemporary examples of this, perhaps because aconitine also has a very bitter taste and is difficult to disguise.  This hasn’t stopped fiction writers from using the poison in their stories and here are a couple of examples: Agatha Christie, in her novel, 4.50 from Paddington, employs aconitine as a murder weapon, pills containing aconitine are substituted for the victim’s sleeping tablets;   in one episode (Garden of Death, 2000) of the popular TV series, Midsomer Murders, aconitine is mixed with fettucine al pesto to dispose of the unfortunate victim.  In 2010, however, a real murder was committed using the poison when Lakhvir Kaur Singh, nicknamed the “curry killer”, poisoned her former lover by mixing extracts of the related plant Aconitum ferox into his leftover curry.

There has been some speculation recently that simply brushing against the plant might be dangerous but this idea has been discredited.  Nevertheless, should the sap of the plant come into contact with skin the poison may be transferred especially through cuts.  Caution should, therefore, be exercised if the plant is encountered in the garden or in the wild as the following anecdote, taken from Richard Mabey’s book Flora Britannica suggests:

In 1993, there was an epidemic of poisoning at a florist’s in Wiltshire.  “A flower seller was treated for heart palpitations in intensive care after handling bunches of a poisonous flower ……… staff at a flower shop in Salisbury suffered shooting pains after poison from a monkshood entered their bloodstreams.  The shop’s owner bought 150 bunches from a wholesaler who has now withdrawn them.  ” I wondered what was wrong – all of a sudden everyone was lethargic and getting pains.” ”

 

the exhibition poster

 

A view of part of the exhibition

 

Hazel’s diptych painting of the Erme estuary

 

My photo of a bloody nosed beetle

 

yellow rattle and catsear in the riverside meadow

 

Two bumblebees feeding from white clover. The one in the foreground is a vestal cuckoo-bee (B.vestalis) based on the thin lemon yellow stripe towards the end of its abdomen