Stinging Nettle



Sting Nettle_COCanal_120408

Common Name: Stinging Nettles, Common nettle, Burn weed – The seemingly innocuous plant exudes a chemical cocktail when touched that induces a painful sensation for which it has earned the epithet of stinging as an avoidance mnemonic. Nettle is a derivative of ‘net’ which ultimately derives from the Sanskrit nahyati meaning knot or weave; nettles have historically been used in the fabrication of a variety of textile products.

Scientific NameUrtica dioica – The Latin word for Stinging nettle is Urtica, a reflection of the antiquated cultural ancestry of the plant; Urtica is derived from the root word urere, which means ‘to burn.’ The species name refers to the fact that the plant is dioecious, having the male and female reproductive components on different plants.

Potpourri: The Stinging Nettle is the doppelgänger of the Kingdom Plantae; it is at the same time a most useful and nutritious of common, weedy forest fare masquerading as a ghostly double of itself, exacting a painful toll to all who touch it. It is one of the easiest plants to identify; the trenchant burning sensation is particularly difficult to characterize, but impossible to ignore. It is a peculiar combination of a sting and an itch that is something less intense than a bee on the pain scale and less calamitous than poison ivy on the irritation scale. A measure of its notoriety is captured in the use of the term nettlesome, which means ‘that which nettles or irritates.’ Although it is fearsome and unforgettable, it is fortuitously ephemeral, fading to a dim if hellacious memory in about a quarter of an hour, depending on the duration of contact and the virulence of the toxins.

What I will call the “nettles effect” is a particularly well engineered evolutionary characteristic of some of the many small trichomes (plant hairs) that cover the leaves and the stem. The stinging hairs operate on a tactile basis; when they are touched the tip breaks off transforming the harmless hair into an injurious needle, injecting whatever it contacted with a rather complex combination of acrid chemicals. The peculiar sensation of the nettle encounter is attributable to the combination of the effects that derive from its many constituents, which include formic acid, histamine, acetylcholine and serotonin. Formic acid is the simplest of the carboxylic acids (HCOOH) and is notable for being found in the venom of bees and ants (the Latin word for ant is Formica). This would be the pain part – a hundred micro-bee stings. Histamines are well known to those with allergies for their part in the immune response (whether you want one or not – antihistamines are what you use to trump them). This would be the redness and itchiness part that is typical of an immune system action. Acetylcholine is a neurotransmitter that is involved with muscle stimulation. This is probably what makes the nettle reaction indescribable, as the muscles tense in synchrony with pain and itch. And finally, thankfully, there is serotonin, which is generally considered to be beneficent for humans – perhaps this is what makes the “nettles effect” dissipate (or maybe this is just psychosomatic since serotonin is also associated with plant and insect venoms). There are innumerable folk remedies for the alleviation of the ouch-itch-twitch of the “ nettle effect” that range from mud and saliva to baking soda and lemon juice, but the most well-known is jewelweed (Impatiens spp) which is fortuitous since they typically occupy the same habitats and grow in close proximity to nettles. However, the nettles effect is after all only a relatively mild and short-lived discomfort that is best dealt with in the traditional British manner – with a stiff upper lip.

The good in Stinging nettles far supplants the bad in both gastronomical and medicinal applications; in fact, it should perhaps be more appropriately called ‘wholesome nettle’ or ‘heal-all nettle.’ The edibility of the nettle is the more surprising of its attributes, as common sense would imply that ingesting something so tainted with toxins would be an exercise in gustatory Russian roulette, akin to the Japanese penchant for eating the poisonous blowfish called fugu, assuming that the chef cut out all the bad parts. The key to the seeming contradiction is the application of heat, as cooking drives off the harmful volatile constituents of the “sting” as vaporous emissions. What emerges is a potherb of superior quality that has been described as having the taste and texture of cucumber-like spinach. However, although taste is an important attribute, it is not the sine qua non of food – that is relegated to its nutritional value – which is prodigious. The basic composition of the nettle is about 20 percent protein (if the leaves are dried this rises to a gargantuan 40 percent), 15 percent fiber, 25 percent ash, 4 percent fat with a balance of assorted non-nitrogen compounds. Rigorous chemical analysis has revealed the presence of more than 50 chemical compounds. The leaves are notable for high levels of vitamins A and C, but they also contain significant amounts of the entire alphabet soup of “vital amines” including B-1 thiamin, B-2 riboflavin, B-3 niacin, B-6 and B-12, D, E, F, K and P. The minerals are similarly ubiquitous, as nettles are noted for high levels of magnesium, iron, zinc and selenium supplemented by substantive levels of iodine, chromium, copper, sulfur and boron. With 16 amino acids thrown in for good measure, one might well rank the stinging nettle as a miracle food, the breakfast of (hiking) champions. There is one caveat. The nettle should only be harvested in the early stages of vernal growth. Maturity at the advent of the summer solstice is indicated by the production of flowers, seeds, and inorganic calcium carbonate concretions called cystoliths; the latter, if ingested, can irritate the urethra, an unpleasant experience at best. The flowers, though not of particular note, are quite obvious, a disheveled mass of small white florets extending out on asymmetrical branches midway up the main stem.

The Stinging nettle has an enduring history as a panacea dating from Greco-Roman antiquity. Claudius Galenus – better known as Galen – was the Greek physician of the Roman emperors in the second century CE and perhaps the most prolific and certainly the most well-known of the ancient medical authorities. In the herbal of Galen, which is commonly known as De Simplicibus, the nettle is recommended as a cure for everything from gangrenous wounds and dog bites to asthma and mouth sores. His Greek predecessor Hippocrates listed over sixty remedies. As the translated works of Galen and Hippocrates became the fons et origio of medicine in the Dark and Middle Ages, the use of nettles expanded in proportion to the acculturation of earliest tribal communities. By the time of 17th Century English herbalist Nicholas Culpepper, the nettle became the cure-all of the nascent medicine cabinet, good for sore throat gargles, gout, aches and pains, and as an antidote to the venomous sting or bite of almost anything. But the most creative if seemingly masochistic use that emerged was to beat oneself with nettles, a practice known as urtication, which, according to Webster’s Dictionary is “the flogging of a paralyzed limb, etc. with nettles for the stimulating effect produced.” One account purports that the Roman soldiers stationed on the British Isles urticated their legs after long marches to alleviate the pain. While the strength and endurance of Roman soldiers was doubtless prodigious, legend is the breeding ground of apocrypha. However, there is likely something to this, as pain in one part of the body can draw both conscious and neural attention away from an alternative, perhaps more troublesome source, such as arthritis. There is some evidence that the nettle alters the inflammatory effect of the body’s “humors.” The Peterson Field Guide Medicinal Plants and Herbs offers the observation that “some people keep potted Stinging Nettle in the kitchen window, alongside an aloe plant, in the belief that an occasional sting alleviates arthritis.” Just to provide a balanced view, the guide also provides a cautionary note: “One fatality has been attributed, rightly or wrongly, to the sting of a larger tropical nettle.”


Sting Nettle in full flower

The profusion of medicinal uses of the Stinging Nettle on a global scale is not likely attributable to a widespread contagion of a delusional placebo effect. It is much more likely that the nettle has manifest benefits that have been discovered through trial and error. The application of the scientific method characteristic of the last century has indeed confirmed that nettles are good medicine. Numerous clinical studies (one with over 200 patients) have been conducted to demonstrate the efficacy of nettles in the treatment of rheumatoid arthritis pain as an alternative to commercial drugs – it has been approved in Germany as a treatment for this condition for quite some time. A more recent development (also of German inauguration) is for the use of nettles in the treatment of benign prostatic hyperplasia (BPH) better known as an enlarged prostate, the bane of aging males. One trial involving over 500 patients found substantial increases in the urinary flow (which an enlarged prostate blocks) and a decrease in what is euphemistically called micturition which is, in the vernacular, nighttime urination. A third relatively new application based on Australian herbalism consisted of a test of the efficacy of nettle in the treatment of asthma. A double blind study of 98 patients in Oregon confirmed asthma amelioration in the 1990’s. There are probably many other potential applications awaiting a proper trial to confirm that the traditions of historical herbalism based on the evidentiary long term trials of population dynamics are valid. Numerous references extol the virtues of the Stinging nettle on the action of the lymphatic system to enhance immune responsiveness and on its renal beneficence in the extraction of wastes. It is a weed wunderkind waiting to happen.

The usefulness of the Stinging nettle does not end with its edibility, nutritional qualities and medical potentiality, though these attributes alone would qualify it as highly endowed. Nettle has been made into various textile products (whence the name nettle derives) for millennia; evidence for this was the discovery of burial shrouds made from nettles that were unearthed in Denmark dating from the Bronze Age of prehistory. Nettle fibers are made from the stalk by removing the covering to reveal individual fibers that can then be braided by overlapping until a ropey twine is formed. The twine can then be woven into sheets in a manner similar to the making of linen from flax or, alternatively, enlarged into ropes. It is noted by B. Angier in Edible Wild Plants that “nettle fiber ropes prepared in this way have been used to move stones in excess of 20 tons.” Nettle fabric has been widely used in Europe since the Dark Ages though it has fallen into desuetude due to the plethora of synthetic alternatives. However, during World War I, the blockaded German Army of necessity reverted to nettles due to the shortage of cotton; it is reported that fully 85 percent of captured German uniforms were made from nettle. Once the nettle fabric is made, it can be dyed green with nettle, which has almost 5 milligrams of chlorophyll in every gram, one of the highest percentages in nature. During World War II, the British requisitioned 100 tons of nettles to make green dye for camouflage. And, as if this were not enough, nettle extract is restorative to hair follicles and is widely used in hair conditioners; Clairol is reported to use about 40 tons of nettles a year.