|
The stinging nettle (Urtica dioica), known variously as tall nettle, California nettle, slender nettle, and bull nettle (a name shared by Cnidoscolus texanus and Solanum carolinense), is the best known member of the nettle genus Urtica. It is an invasive herb native to Europe, Asia, and North America, and has been introduced to South America.
Taxonomy
The taxonomy of stinging nettles has been confused, and older sources are likely to use a variety of systematic names for these plants. Formerly, more species were recognised than are now considered defensible. However, there are at least three clear subspecies, formerly classified as separate species:
- European stinging nettle U. dioica ssp. dioica
- American stinging nettle U. dioica ssp. gracilis (Ait.) Selander
- Hairy nettle U. dioica ssp. holosericea (Nutt.) Thorne.
Other former species names that are now regarded as synonyms of U. dioica include breweri, californica, cardiophylla, lyalli, major, procera, serra, strigosissima, trachycarpa, and viridis.
Range
The subspecies U. d. dioica is native to Europe, while U. d. gracilis and U. d. holosericea are native to North America. In northern Europe the stinging nettle is ubiquitous, found everywhere in the countryside and colonising any patch of neglected ground in urbanized areas. In North America it is widely distributed in the United States, where it is found in every state except for Hawaii, Arkansas, and South Carolina). However, in North America stinging nettles are markedly less common than in northern Europe. The European subspecies has also been introduced into North America.
Biology
The soft green leaves of the stinging nettle are covered with hollow, silky hairs that contain formic acid as a defense against grazing animals. Bare human skin brushing up against a stinging nettle plant will break the delicate defensive hairs and release the acid, usually resulting in a temporary and painful skin rash. The folk remedy for the sting is to wrap the affected part in the leaf of a dock (Rumex obtusifolia), which commonly grows in association with nettles.
Practical uses
Despite its sting, the nettle is a plant with many uses. It is recommended by the herbalists of many different cultures for a wide variety of purposes in herbal medicine. Cooking, crushing or chopping disables the stinging hairs, and the leaves are not only tasty, but high in nutrients. The young leaves are edible and make a very good pot-herb. A simple recipe is to gather the upper stalks including 3-4 pairs of leaves before the plants flower (using gloves), until one has enough to entirely fill a small saucepan. Fill the pan with cold water, and then put on a lid and drain off the water until all that remains is what is clinging to the leaves. Then put the pan on high heat and steam the leaves, shaking the pan occasionally, until all the leaves are wilted. The leaves can be dried and used to make a tisane. Nettle stems contain a bast fiber which has been traditionally used for the same purposes as linen, and is produced by a similar retting process. Nettles can also be used as cattle fodder; cows appear to find harvested nettles a delicacy.
Influence on language and culture
In England the nettle is the only common stinging plant, and has found a place in several figures of speech in the English language. To "nettle" someone is to annoy them. Shakespeare's Hotspur urges that "out of this nettle, danger, we grasp this flower, safety" (Henry IV, part 1, Act II Scene 3). The common figure of speech "to grasp the nettle" probably originated as a condensation of this quotation. It means to face up to or take on a problem that has been ignored or deferred. It metaphorically refers to the fact that if a nettle leaf is grasped firmly rather than brushed against, it does not sting so readily, because the hairs are crushed down flat and cannot penetrate the skin.
Urtica dioida
from Thomé Flora von Deutschland, Österreich und der Schweiz 1885 External links
|
