Formic acid is one of the chemicals present in nettle stings, along with histamine and acetylcholine. This chemical cocktail is delivered via stinging hairs with tips that break off when touched. This transforms them into needles which then inject the sting into the skin. Formic acid is also found in bee, wasp and ant stings.
Nettles are an excellent source of vitamins and the young leaves taste like spinach. Soaking the leaves in water or cooking removes the stinging chemicals, allowing the nettles to be safely enjoyed.
Nettles have also been used as a source of green and yellow dyes, and fibres from mature stems can be woven into cloth. During World War I, when there was a shortage of cotton, nettlecloth was reportedly used to make German soldiers' uniforms.
At the Botanic Garden, we cultivate nettles in their family bed, Urticaceae, on the Systematic Beds but nettles also play an important role ecologically in the long grass and hedgerow plantings, providing the food plant for several insect larvae, including the caterpillars of the Peacock butterfly.