Bothered by brambles and snagged by sow thistles, but what is the point of all this thorny microaggression?

Poor old Theodore Oswaldtwistle the thistle sifter who, when sifting a sack of thistles, thrust three thorns through the thick of his thumb. This old tongue-twister, once used by P. G. Wodehouse’s Bertie Wooster to check on Jeeves’s sobriety, holds a painful truth. Nature’s thorns, spikes and prickles have the potential to leave us feeling sore.

If you’ve ever been snagged by a sow thistle or bothered by a bramble, you may, as you remove the barbs and unpick the prickles, be asking Nature: what is the point of all of this thorny microaggression? The blunt answer is self defence. Plants that don’t want to be eaten can employ various tactics. They can use chemical weapons — producing compounds that make them bitter, poisonous or unpalatable — or they may develop sharp and irritating protrusions to deter hungry herbivores.

‘The stem thorns of the hawthorn are a great example and protect the leaves from herbivores such as deer,’ notes Paul Rees, nursery manager of living collections at the Royal Botanic Gardens, Kew. He goes on to explain that, as well as thorns and prickles, which are technically different, some leaf petioles and flower stalks can dry and harden to form thorn-like structures and some leaves may have sharp rigid tips or margins. An example is holly, which generally has pricklier leaves at a lower level and smoother leaves higher up the tree, out of the reach of cattle and deer.

Animal browsers will avoid thorns, although goats, with their tough, specially adapted lips, tongues and digestive systems, seem to relish tackling a blackberry bush. This plant also uses its prickles to scramble and latch onto nearby neighbours, Paul explains.

As is so often the case, we have made an ally of Nature’s attempts to disadvantage us. Thorny shrubs such as blackthorn — the clue to its bristliness is in its Latin name, Prunus spinosa — and hawthorn make excellent hedging. According to West Country hedgelayer Paul Lamb, author of the book Of Thorn & Briar, thorny species should make up at least 60% of a good stockproof hedge. He works predominantly in the Midland style of hedgelaying, whereby the thorny ends of each plant are directed into the field where livestock are kept, confronting them with an impenetrable wall.

Injurious thorns are an occupational hazard. ‘Blackthorn makes a great hedgerow and habitat, but its thorns carry the highest risk of infection,’ he warns. ‘A deeply embedded thorn, if not removed, will fester and need treating with antibiotics. A thick tweed cap will offer some protection to the head, and glasses should also be worn. A thorn in the eye doesn’t bear thinking about.’ Artist Sir Alfred Munnings would concur: he lost the sight in one eye as a young man when bending down to lift a puppy over a stile.

Flower arrangers habitually deal with the prickly problem by using a thorn stripper, a tool that grips the stem and shears off prickles, although some florists specialising in British seasonal flowers think thorns give them an edge. Veronique Foulds from Flower & Press, a floral design studio in London that provides arrangements for high-end weddings and events, loves to use briar roses in early summer: ‘They have such a beautiful shape, which you can’t get from any other rose.’ In winter, the stakes are lifted higher with the use of tall teasels, with their prickly stems and spiky seedheads, for dramatic effect.

Humans have learned from the protectiveness of thorns. The spiked dog collar — imagine Spike the bulldog from Tom and Jerry cartoons or the adornment beloved of punks and goths — was developed with a serious purpose. The spikes were originally designed to prevent an attacking wolf from getting a good grip on a canine’s neck and the collars are still worn by flock-guarding dogs in remote areas of Turkey. In Switzerland, where wolf numbers have been increasing, sharp anti-wolf collars have been developed for goats, sheep and cows.

We have also copied the thorn in order to weaponise it. The 14th century saw the invention, in Germany, of the morgenstern, or ‘morning star’: a club or mace with a spiky metal ball attached to its shaft, able to combine blunt force with puncturing power. This developed into the flail, the bristly head of which was attached to a chain for greater swinging power. Barbed wire, our manmade version of the thorny fence, was developed by Joseph Glidden in Illinois in 1873. The spiked wire fencing has since served as cheap stock proofing, as well as to hideous effect during the First World War.

The Scots have found thorns to be of assistance in the tale of how the thistle became the symbol of the nation. Long ago, as an invading Norse army crept barefoot through the night intent on a surprise attack, one of its soldiers is said to have stepped on a thistle and let out a giveaway cry. Thus the flower of Scotland, with its spear-tipped leaves and bracts, became a symbol of vigilance and resilience. Another thistle lover is Eeyore from A. A. Milne’s ‘Winnie-the-Pooh’ stories, who enjoys eating them so much he reserves ‘the most thistly looking patch of thistles that ever was’ for his birthday treat.

Perhaps the most famous thorn-adjacent legend is that of Sleeping Beauty, who pricks her finger on a spindle and drifts to sleep for 100 years as an impenetrable thicket grows up around her. There is a puzzle about how the soporific prick could have happened. A spindle is a wooden stick — traditionally made from the thornless spindle tree — used for spinning wool. Although it is carved to a taper at each end, it is never sharp enough to puncture skin: there would (literally) be no point in it being so lethal.

We have to respect Nature’s invention of the safeguarding thorn, even if we get a rogue one thrust into a thumb on occasion. Should you get a ‘raw paw’, as Baloo the Bear sings in Disney’s The Jungle Book… ‘Well next time, beware!’