Arctostaphylos uva ursi. Uva Ursi.
Nat. Ord. — Ericaceae. Sex. Syst. — Decandria Monogynia.
Description. — This plant, known also as Bearberry, Upland Cranberry, etc., is a low, evergreen shrub, with a perennial, long, fibrous root ; the stems are procumbent, round, woody, and branched, covered with a smooth, deciduous bark. The leaves are numerous, alternate, evergreen, obtuse, obovate, entire, coriaceous, smooth, dark-green and wrinkled above, reticulated and paler beneath, acute at base, and supported on short petioles. The flowers grow in small clusters at the extremities of the branches, each on a short, red, reflexed peduncle, furnished with several minute bracts ; they are usually six to twelve on each branch, drooping, and of a pale rose color. The calyx is small, obtusely five-toothed, persistent, and of a reddish color. The corolla is ovate or urceolate, smooth, white with a reddish tinge, transparent at the base, contracted at the mouth, hairy inside, with five short, reflexed segments. The stamens are ten, with subulate downy filaments inserted at the base of the corolla, and reddish incumbent anthers, of two oval cells, opening by two terminal pores, and furnished with a pair of short horns or spurs.
The ovary is roundish, bearing a cylindrical erect style, with a simple stigma. Disk a black indented ring. Fruit small, globose, smooth, depressed, scarlet, containing a mealy pulp of an austere or insipid taste, and five almost united angular seeds. This plant is the Arbutus Uva Ursi of Linnaeus, and Willdenow, from which it was separated by Sprengel, principally on account of the difference of its berry.
History. — The Uva Ursi is a perennial evergreen, common in the northern part of Europe, Asia, and America, growing on barren, gravelly hills, and elevated sandy plains. It flowers from June to September, and ripens its berries during the winter. The leaves are the only part used in medicine, they should be collected in autumn, and the green leaves only selected. They are about an inch long, and two to three lines wide, often spatulate in form. They are sometimes adulterated with the leaves of the whortleberry or cowberry, Vaccinium Vitis Idaea, from which they may be detected, by the rounder shape, and the revolute edges of the Vaccinium, and by their being dotted beneath instead of reticulated as in the genuine leaves. Leaves of the Chimaphila Umbellata may be determined by their greater length, their cuneiform lanceolate shape, and their serrate edges.
The leaves of Uva Ursi when dried have a faint odor like hay, and a bitterish, strongly astringent taste, which becomes finally sweetish. Their powder is of a yellowish-brown color. Analysis has discovered in them gallic and tannic acids, resin, gum, bitter extractive, some salts, volatile and fixed oils, lignin, and a peculiar principle, called ursin, which contains its diuretic power. The leaves yield their properties to water or alcohol.
Ursin, is said by J. C. C. Hughes, to be prepared as follows ; macerate one pound of the leaves of Uva Ursi in water for twelve hours, and displace until two quarts of liquor are obtained. Then precipitate the tannin with a solution of gelatin, and filter. Evaporate the filtered liquor to dryness, and dissolve the remaining extract in strong alcohol, and treat it with purified animal charcoal for twenty-four hours. Again filter, evaporate, and redissolve in absolute alcohol, and treat again with purified animal charcoal for twenty-four hours ; filter and crystallize by spontaneous evaporation. Press the crystals, redissolve in absolute alcohol, treat with animal charcoal, filter, and again crystallize by spontaneous evaporation. The crystals are colorless, transparent, needleshaped prisms, soluble in alcohol, ether, and dilute acid, but insoluble in fixed and essential oils. Subacetate of lead and carbonate of potassa precipitate its aqueous solution ; lime-water, and tincture of chloride of iron do not affect it. It is neutral to test-paper, and combustible. One grain acted as a powerful diuretic. Arbutin and Arctuvin have also been obtained from the leaves by Kawalier, but their therapeutical influences are not positively known.
Properties and Uses.—Uva Ursi is an astringent, tonic, and diuretic. As an astringent it is applicable to all the purposes for which astringents are used, as in chronic diarrhea and dysentery; diabetes, and menorrhagia. Its principal use however is in chronic affections of the kidneys and urinary passages, in vesical catarrh, chronic gonorrhea, gleet, leucorrhea, incontinence of urine, strangury, and in excessive mucous discharges. It changes the color of the urine, and its astringent principle has been detected in that secretion, also reputed efficacious as an antilithic in calculous affections. In gonorrhea, with bloody and mucous discharges, and pain in the vesical region, it speedily allays all these unpleasant symptoms. Dose of the powder ten to sixty grains ; of the decoction, one to three fluidounces, made by boiling one ounce of Uva Ursi with a pint and a half of distilled water to a pint ; of the extract five to fifteen grains.
Off. Prep. — Decoctum Uvae Ursi.