THE POISON GARDEN website      Arum maculatum berries on a Cannabis leaf 

Search thepoisongarden.co.uk:

This free script provided by JavaScript Kit

Pontifications on Poison

Being some ramblings on events associated with poisonous plants.

Tuesday 22nd May 2012

I spoke too soon. When I said Wednesday that my talks ‘season’ had ended I reckoned without getting a fairly short notice request to talk to a Rotary Club later this week.

It is an after dinner event with the request being for twenty minutes with no visual aids and I’m still trying to decide what to pick out for inclusion. The real skill, that I’m not sure I possess, is to say just enough to whet appetites so that there are plenty of questions at the end.

Urtica dioica, stinging nettle

Urtica dioica, stinging nettle

Regardless of the subject or the format, I start every talk with Urtica dioica, stinging nettle. It gets so many things on the table straightaway. Many people don’t think of it as a poisonous plant even though they know it causes pain so you are immediately into the difference between ‘poisonous’ and ‘deadly poisonous’.

The way it causes the sting is not what many people think so you get into false beliefs about plants and, in fact, the full mechanism of the stinging is still not understood so you can illustrate that our knowledge of how plants do what they do is incomplete.

Then there is the idea that rubbing a sting with a leaf from Rumex obtusifolius, dock, will cure it bringing up both the folklore of plants and the irrational beliefs people hold onto about ‘natural’ remedies.

And, I use stinging nettle to illustrate a key point about the use of potentially harmful substances. Since everyone knows that Urtica dioica will cause pain if given the chance, why do so many people give it the chance? Do they think it harms other people not them? Are they so desperate to get where they feel they need to go that they will accept the need to walk through a patch of nettles to get there? Do they convince themselves that the plants obstructing their path are actually Lamium orvala, deadnettle, rather than stinging nettles so there is nothing to fear?

Urtica dioica, stinging nettle

Urtica dioica, stinging nettle

And then there is what is known about how stinging nettle stings, a story dealing with the wonderful complexity of nature. Each of the tiny stinging hairs on the underside of the leaves is a sort of sealed hypodermic syringe consisting of a hollow needle with a brittle top and a bulb containing histamine, acetylcholine and 5-hydroxytryptamine. If you brush across the top of one of these hairs the top breaks off leaving a sharp end that sticks into the skin. The sideways action acts like pulling a lasso tight around the bulb so that the toxins are squeezed up the tube and into the skin.

The sideways movement seems to be an essential part of getting stung meaning there is some truth in the adage about grasping the nettle because, by so doing, you simply flatten the hairs rather than causing the tips to break off.

I’ve written before that many people say that the Romans introduced the stinging nettle to the UK but, as I pointed out, there is evidence that it was found in northern Europe long before the days of the Roman empire. I’ve just read another reference to it suggesting that it was found in what could be called Britain long ago.

Urtica dioica, stinging nettle

Urtica dioica, stinging nettle showing the
stinging 'hairs'

I’ve been reading the copy of Granta that Kris Hofmann was kind enough to send me. One of the pieces I’ve read, so far, is Robert Macfarlane’s account of a walk along a footpath in the sea off the coast of Essex. Macfarlane explains that during the last ice age so much of the earth’s water was locked up in glaciers that sea levels were over 100m lower than they are today. Off the Essex coast, this exposed a large area of land called Doggerland and studies of the seabed have shown that stinging nettles grew here ten thousand years before the Roman invasion.

It occurs to me that I could, probably, fill my twenty minutes just with the Urtica dioica but I don’t think that is what they want to hear about. We’ll have to see if I can make it teasing enough to ensure a question at the end.

Follow @thepoisongarden on Twitter

Full Entries

2016

Tuesday 25th October 2016 Saturday 20th August 2016 Sunday 6th March 2016 Wednesday 3rd February 2016

2015

Saturday 28th November 2015 Friday 27th November 2015 Monday 17th August 2015 Wednesday 15th July 2015 Friday 26th June 2015 Thursday 25th June 2015 Thursday 30th April 2015 Wednesday 29th April 2015 Wednesday 11th March 2015 Tuesday 3rd March 2015 Saturday 28th February 2015 Sunday 22nd February 2015

November 2014

Monday 24th November 2014 Saturday 8th November 2014

October 2014

September 2014

Wednesday 24th September 2014 Monday 1st September 2014

August 2014

Tuesday 26th August 2014 Saturday 16th August 2014 Tuesday 5th August 2014 Friday 1st August 2014

July 2014

Sunday 27th July 2014 Wednesday 23rd July 2014 Sunday 13th July 2014 Sunday 6th July 2014 Tuesday 1st July 2014

June 2014

Wednesday 25th June 2014 Tuesday 24th June 2014 Sunday 22nd June 2014 Monday 9th June 2014 Wednesday 4th June 2014

May 2014

Monday 26th May 2014 Sunday 18th May 2014 Wednesday 14th May 2014

April 2014

Sunday 13th April 2014 Saturday 5th April 2014 Thursday 3rd April 2014 Tuesday 1st April 2014

March 2014

Monday 31st March 2014 Tuesday 25th March 2014 Friday 21st March 2014 Monday 17th March 2014 Sunday 16th March 2014 Tuesday 11th March 2014 Thursday 6th March 2014 Wednesday 5th March 2014 Saturday 1st March 2014

February 2014

Thursday 27th February 2014 Monday 24th February 2014 Wednesday 19th February 2014 Monday 17th February 2014 Thursday 13th February 2014 Monday 4th February 2014 Monday 3rd February 2014 Saturday 1st February 2014

January 2014

Thursday 28th January 2014 Thursday 23rd January 2014 Friday 17th January 2014 Wednesday 15th January 2014 Monday 13th January 2014 Thursday 9th January 2014 Tuesday 7th January 2014 Wednesday 1st January 2014

December 2013

Monday 23rd December 2013 Friday 20th December 2013 Tuesday 17th December 2013 Friday 14th December 2013 Thursday 12th December 2013 Sunday 8th December 2013 Wednesday 4th December 2013 Sunday 1st December 2013

November 2013

Friday 29th November 2013 Wednesday 27th November 2013 Tuesday 26th November 2013 Friday 22nd November 2013 Monday 18th November 2013 Friday 15th November 2013 Thursday 14th November 2013 Sunday 10th November 2013 Thursday 7th November 2013 Wednesday 6th November 2013 Friday 1st November 2013

October 2013

Thursday 31st October 2013 Sunday 27th October 2013 Wednesday 23rd October 2013 Monday 21st October 2013 Friday 18th October 2013 Friday 11th October 2013 Wednesday 9th October 2013 Tuesday 8th October 2013 Monday 7th October 2013 Tuesday 1st October 2013

September 2013

Monday 30th September 2013 Saturday 28th September 2013 Friday 27th September 2013 Monday 23rd September 2013 Sunday 15th September 2013 Monday 9th September 2013 Sunday 8th September 2013 Tuesday 3rd September 2013 Sunday 1st September 2013

August 2013

Tuesday 27th August 2013 Sunday 25th August 2013 Monday 19th August 2013 Friday 16th August 2013 Tuesday 13th August 2013 Friday 9th August 2013 Friday 2nd August 2013 Thursday 1st August 2013

July 2013

Saturday 27th July 2013 Sunday 21st July 2013 Wednesday 17th July 2013 Monday 15th July 2013 Saturday 13th July 2013 Friday 12th July 2013 Thursday 11th July 2013 Wednesday 10th July 2013 Tuesday 9th July 2013 Saturday 6th July 2013

June 2013

Friday 28th June 2013 Tuesday 25th June 2013 Friday 21st June 2013 Thursday 20th June 2013 Wednesday 19th June 2013 Saturday 15th June 2013 Sunday 9th June 2013 Saturday 8th June 2013 Saturday 1st June 2013

May 2013April 2013 March 2013 February 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 blog June 2012 blog May 2012 blog April 2012 blog March 2012 blog February 2012 blog January 2012 blog December 2011 blog November 2011 blog October 2011 blog September 2011 blog August 2011 blog July 2011 blog June 2011 blog


IMPORTANT NOTE

The POISON GARDEN website is not connected with Alnwick Garden Enterprises Ltd and/or The Alnwick Garden Trust.