Monday, 11 April 2016

The vicious tale of stinging nettles


Most people will recognise these marks as the calling card of the Urtica Dioica AKA the stinging nettle. This annoyance to many can be found in most forests around the UK, stinging unassuming ramblers for hundreds of years. This entry into the Woodland Science Guide will look closely (not too close obviously) at the common stinging nettle to understand why it is so effective in hurting us.

Here is an extreme close up of the surface of a stinging nettle leaf using a colour enhancing electron micrograph. As you can see, there is an incredible amount sharp hairs in this small section of leaf, all of which resemble a hypodermic needle. What may not be as obvious is that these hairs are actually hollow tubes. Due to the hairs having walls comprised of silica, essentially transforming the hair into a very sharp and easily broke needle. Much like a needle, the hairs will inject chemicals into whomever should be careless enough to snap it. Stored in a bulb at the base of the hairs, chemical such aacetylcholine and hydroxytryptamine are forced into the unsuspecting party, which can cause instant pain and discomfort. Accompanying this cocktail of fun is histamine, which brings on inflammation and can cause further discomfort in the form of a burning sensation.

Despite these damning traits, stinging nettles do have their uses. As cooking destroys their harmful chemicals, nettles can be used to make a nice soup that is rich source of iron and an invaluable source of vitamin C. Research is also being carried out into the possibilities of using nettles to relieve the painful symptoms of arthritis.

To sum up, although the plant can be painful to many unsuspecting people, we should hold off on the shears (for the moment at least) as it may be that the stinging nettles will help many people in years to come.

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