Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..
Dear Readers, I can scarcely believe that I have never featured stinging nettle on The Wednesday Weed , but it seems that it is so. Maybe I have been deterred by the sheer amount that there is to say about this most ubiquitous of ‘weeds’, which has featured in so many of our stories and which has been utilised by us in so many ways. In fact, there is so much to say that, for the first time ever, I am going to feature stinging nettle in two posts, with the second one being published next Wednesday. This week, I am going to concentrate on the thing that makes the nettle most memorable: it’s ability to sting.
It is actually quite unusual for plants to be as fierce in their defence as the stinging nettle is. I vividly recall my first encounter: my Dad had taken over a neglected allotment in Manor Park, East London, close to the towering gas holders. The whole family descended on it one sunny afternoon to clear the waist-high weeds. I grasped a handful of an innocuous looking plant, and felt it stab the palm of my hand. Even as I watched, great blisters came up on my wrists and inner arms. Dad stopped to see what all the wailing was about, and then grabbed a handful of dock leaves and crushed them onto the affected parts. It didn’t quite make it stop hurting, but it was definitely better afterwards, for perfectly valid scientific reasons which are described below.
Today, I was double-checking the foliage of my ‘nettle patch’ to make sure that it was stinging nettle, and so I have a couple of stings on my fingers. They are tingling even as I write. Maybe they will make my prose even more deathless than usual. Well, I can hope.
The leaves and stem of a stinging nettle arecovered in hairs, some of which sting and some of which do not. When the stinging hairs come into contact with something (like a human hand, for example), the ‘cap’ of the hair is broken off, and the sharp point that remains injects chemicals into the skin.
The mixture of ingredients includes a histamine, acetylcholine ( a neurotransmitter), and possibly formic acid. Treatment with an anti-histamine cream will help to alleviate the symptoms,but I find to my delight that dock leaves contain a natural anti-histamine which does the same job. I don’t know about you, but I find that as I get older, the effect of a nettle sting seems to last for longer, and I’m often still a bit tingly and sore several days after a nettle encounter. However, for me nettles are a quintessential part of a day out in the country: they gather under every stile, spring out from every woodland path and hide among the most innocent of greenery. The cry of ‘stinging nettle, mind your arms’ as we trooped through Wanstead Park as small children was as much part of my childhood as orange and lemon cupcakes and spam hedgehogs (mashed potato covered in spammy ‘spikes’ with tomato ketchup for eyes).
Incidentally, all that business about ‘grasping the nettle’ has never worked for me. I know the theory – that being firm with a nettle means that the stinging hairs will be forced to lay down flat against the stem and so pain will be prevented – but I’ve never known a nettle that had read this piece of folklore. Stroke them or grab them, they’ve always behaved just as uncouthly. A thick pair of gardening gloves and long sleeves work for me, though these nettles will happily sting through cotton and even thin summer trousers.
You might think that big animals like deer and cows would not be deterred by a little thing like a sting, but apparently they are. Although they are covered in fur, the lips and tongue of such animals are tender, and they are no fans of getting them covered in hives. So, the theory is that nettles developed their stings to stop themselves from being eaten. Apparently stinging nettles which grow in areas frequented by livestock develop a higher proportion of stinging hairs than those which are not constantly under threat of grazing. The production of such defences must be metabolically expensive for the plant, which is probably why not many species do it. However, the armoury of our stinging nettle pales into insignificance compared to some of its relatives.
The Stinging Tree or Gympie Gympie (Dendrocnide moroides) of Queensland in Australia has a famously long-lasting and potent sting, and is a member of the nettle family. Here is the testimony of a chap named Ernie Rider, who was slapped in the face and torso by the plant back in 1963:
“For two or three days the pain was almost unbearable; I couldn’t work or sleep, then it was pretty bad pain for another fortnight or so. The stinging persisted for two years and recurred every time I had a cold shower. … There’s nothing to rival it; it’s ten times worse than anything else.”
I must remember this next time I’m complaining about a nettle sting.
The English language has even developed a verb, ‘to nettle’, meaning ‘to irritate or harass’.
The relationship between human habitation and stinging nettles is not accidental. Nettles have a fondness for soil with high levels of phosphate and nitrogen, and so they often indicate spots where humans or animals have urinated or defecated. I think it’s no accident that the finest crop of nettles on the unadopted road in East Finchley is on the corner, a spot where I am willing to bet many chaps have stopped off on their way home from the pub for a wee. It’s said that the outline of Scottish crofts which have otherwise completely disappeared can still be identified by the stinging nettles that grow where the outhouses and middens would have stood, two hundred years after the infamous Highland Clearances took place.
Just a few words here on the sex-life of the nettle. As you might guess from the species name dioica, nettles are dioecious, which means that some nettles have male flowers and some have female flowers. The male flowers often have a purplish tinge at some point in their development and are held quite stiffly away from the plant. They have been described as looking like tiny Brussel sprouts.
The female flowers are in long, drooping catkins, and in full bloom are said to look as if they are covered in hoar-frost.
For some excellent photos of male and female nettles, have a look at The Wildflower Finder website.
The purpose of having separate male and female plants is, as usual, to ensure genetic diversity, by making sure that an individual plant can’t pollinate itself. The inconspicuous and plentiful flowers, and their lack of strong colour and scent, is an indication that this is a wind-pollinated plant, and indeed the pollen has been implicated in hay fever and other allergies. However, it is also used by some practitioners as a powerful anti-allergy agent. As we will see next week, stinging nettle has been used by humans in many ways: medicinally, as food, for clothing and as feed for domestic animals. It is also a critical food for many insects, including some of our most exquisite butterflies. But I would like to finish here with a poem that reflects our uneasy relationship with this plant. Vernon Scannell was a soldier during World War 2, and his poem ‘Nettles’ sums up the very human frustration with the natural world’s refusal to bow to our requirements.
Nettles by Vernon Scannell
My son aged three fell in the nettle bed.
‘Bed’ seemed a curious name for those green spears,
That regiment of spite behind the shed:
It was no place for rest. With sobs and tears
The boy came seeking comfort and I saw
White blisters beaded on his tender skin.
We soothed him till his pain was not so raw.
At last he offered us a watery grin,
And then I took my hook and honed the blade
And went outside and slashed in fury with it
Till not a nettle in that fierce parade
Stood upright any more. Next task: I lit
A funeral pyre to burn the fallen dead.
But in two weeks the busy sun and rain
Had called up tall recruits behind the shed:
My son would often feel sharp wounds again.
Photo One (diagram of nettle hair) – By Peter coxhead – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=27752919
Photo Two (Gympie Gympie Tree) By Cgoodwin – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=3380257
Photo Three (Stinging Nettle with male flowers) – By John Tann from Sydney, Australia (Stinging Nettle) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons)]
Photo Four (Male Flowers) – By Frank Vincentz – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2513951
Photo Five (Female Flowers) – By Frank Vincentz – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2513964
Vernon Scannell Poem taken from https://www.tutorfair.com/blog/gcse-poem-analysis-nettles-by-vernon-scannell
All other blog content copyright Vivienne Palmer. Free to use and share non-commercially, but please attribute and link back to the blog, thank you!