URTICA, the NETTLE; a genus of the tetrandria order, belonging to the monoclea class of plants.
1. The urens, or lesser stinging nettle, grows in waste places, on dunghills, &c. The stings or prickles of this are very numerous and inflammatory; the leaves of a roundish oval figure, and light green colour: the male and female flowers grow in different parts of the same plant, in crowded oblong green clusters, erect, nearly sessile in the axæ of the leaves. The stings are very curious microscopic objects: they consist of an exceedingly fine pointed tapering hollow substance, with a perforation at the point, and a bag at the base. When the spring is pressed upon, it readily perforates the skin, and at the same time forces up some of the acrimonious liquor contained in the bag into the wound.
2. The dioica, or common stinging nettle, grows plentifully in waste places, and under hedges. The male and female flowers grow on distinct plants; the clusters branched, and generally in pairs. The aculei,
or stings of the nettle, have a small bladder at their base, full of a burning corrosive liquor: when touched, they excite a blister, attended with a violent itching pain, though the sting does not appear to be tubular, or perforated at the top, nor any visible liquor to be infused into the puncture made by it in the flesh. It seems certain, however, that some of this liquor is insinuated into the wound, though invisibly, since the stings of the dried plant excite no pain. The chives afford a very pleasing appearance: they are rolled inwards under the segments of the cup, which fold over them till they are ripe, when the segments gradually expanding, the chives released from their confinement, roll back with an elastic force, and discharge the contents of their transparent tips which float in the air like a cloud of dust, that it may arise to the summits of the fertile flowers.
Nettle-tops in the spring are often boiled and eaten by the common people instead of cabbage-greens.
In Arran, and other islands, a rennet is made of a strong decoction of nettles: a quart of salt is put to three pints of the decoction, and bottled up for use. A common spoonful of this liquor will coagulate a large bowl of milk very readily and agreeably. The stalks of nettles are so like in quality to hemp, that in some parts of Europe and Siberia they have been manufactured into cloth, and paper has been made of them. The whole plant, particularly the root, is esteemed to be diuretic, and has been recommended in the jaundice and nephritic complaints. It is also reckoned astringent; and of service in all kinds of haemorrhages, but is at present but little in practice. The roots boiled will dye yarn of a yellow colour. The larvæ, or caterpillars of many species of butterflies, feed on the green plant; and sheep and oxen will readily eat the dried.