I was out with the dog one fine evening recently and we entered a field of cattle. I am normally wary of a canine-bovine interaction but, on this occasion, valour overcame discretion and we continued on our way.
I had, however, underestimated the curiosity of frisky bullocks and, to my dismay and to Skye’s terror, the creatures mobbed us. We beat a difficult retreat, which involved negotiating a barbed wire fence, a muddy ditch and a large patch of nettles.
Unfortunately, I was wearing shorts, and I suffered well into the next day. Inevitably, nettles were brought to the forefront of my thoughts.
The stinging nettle, Urtica dioica (Latin urere, “to burn”), has hollow trichomes whose tips come off when touched, transforming the hair into a needle that will inject a cocktail of chemicals, including acetylcholine, histamine, 5-hydroxytryptamine and formic acid.
Nettles do, however, have their benefits. They can reduce musculoskeletal pain, if applied to the afflicted area, by affecting transmission at nerve endings or by an acupuncture-type effect. They act as a counter-irritant like capsaicin.
Roman soldiers used the warming effect of stinging nettles to adapt to the cold, damp British climate. Nettle leaf extract reduces inflammation in arthritis, and root extract can be used to inhibit benign growth of the prostate and alleviate associated inflammation.
Cooking, drying or chopping disables the stinging hairs. Nettle leaf soup is rich in nutrients and has a flavour similar to spinach. The young leaves make a good pot-herb and the dried leaves or flowers make a nourishing herbal tea. Nettle stalks contain strong fibres similar to flax. They have been used in the manufacture of cloth, sails and twine.
The high nitrogen content makes nettles a valuable addition to the compost heap and a useful ingredient of liquid manure.
The nettle is commonplace and is an untapped resource in these days of rising commodity prices.
Nettles can serve archaeologically by indicating the site of long-abandoned buildings. Human and animal waste will elevate phosphate and nitrogen levels in the soil and provide an ideal environment for the plant. The sites of Scottish Highland crofts razed to the ground during 18th century clearances can still be identified by this means.
