Botanical Source.—This plant is a small shrub, about 3 or 4 feet in height, with several simple, straight, round, ferruginous-tomentose, hard, brittle stems. The leaves are alternate, simple, ovate-lanceolate, smoothish and dark-green above, rusty white with a dense tomentosum beneath, unequally serrate, crowded, on short petioles-they are 1 ½ to 2 inches in length, and about one-half as wide. The flowers are small, very numerous, light-purple or rose-colored, in a short, dense, slender, terminal spike, or pyramidal cluster of some beauty. Stamens numerous, exserted, and conspicuous., styles 5; carpels 5, distinct, and woolly; seeds awl-shaped at each end (W.—G.).
History.—This is a beautiful shrub, common in low grounds and moist meadows, throughout the United States, flowering from May to August. The herbaceous part is used, especially the leaves and bark. It has an odor somewhat resembling that of black tea, and a very astringent, bitter taste, which properties it imparts to boiling water in infusion. It appears to contain tannic and gallic acid, volatile oil and bitter extractive. The fruit is persistent, remaining through the winter, and furnishing food for the snowbird.
Action, Medical Uses, and Dosage.—Hardback has been found an excellent astringent in summer complaint of children, diarrhoea, and other diseases requiring this class of remedies, and is less offensive to the stomach than most agents of this kind. It has likewise proved efficient as a tonic in cases of debility, convalescence from diarrhoea, dysentery, etc., and to improve the digestive functions. Passive hemorrhages, and menorrhagia have been treated with it, while as an injection good results have been obtained from its use in gleet and leucorrhoea. It is generally given in infusion, the dose being 1 or 2 fluid ounces. A very elegant extract, not inferior to catechu, may be made by carefully evaporating an infusion made by percolation, and which may be given in doses of from 2 to 20 grains. A tincture, well representing the virtues of spiraea, may be prepared from 8 ounces of the fresh leaves and bark to 1 pint of 76 per cent alcohol.
Related Species.—Spiraea Ulmaria, Linné. This plant bears small white flowers in corymbs supported on long peduncles. It is indigenous to Europe, where it is known as Meadow-sweet and Queen of the meadow. It has been introduced into this country and is frequently found in cultivation, in which case the flowers are usually double. The chief constituent of this plant is oil of meadow-sweet, first observed in 1835 by Pagenstecher. It is heavier than water, strongly aromatic, solidifies at -20° C. (-4° F.), and produces a deep-violet color with solution of ferric chloride. It consists chiefly of salicylic aldehyde (C6H4OH.CHO) (Dumas, Ettling, 1839), formerly called salicylous acid; some free salicylic acid, a small quantity of methyl salicylate (Schneegans and Gerock, 1892), and traces of piperonal (see Piperinum) and vanillin; also very little of a camphor-like body and a terpene (Ettling). According to Schneegans and Gerock, salicylic aldehyde does not preexist in the flowers, but is formed during distillation by the action of a ferment upon a substance as yet unknown; it is not salicin. (See details regarding the chemistry of the oils obtainable from the different parts and species of Spiraea, in Gildemeister and Hoffmann, Die Aetherischen Oele, 1899, p. 550). This plant is diuretic, astringent and tonic. It has been employed in fevers, like Virginia snakeroot, in dropsy, and in retention of urine due to prostatic enlargement. It relieves urino-genital irritation, influences the prostate gland checking prostatorrhoea, and is useful in gleet, chornic cervicitis, and chronic vaginitis with leucorrhoeal discharges.
Spiraea filipendula, Linné.—Europe. The pyriform or moniliform tubers found upon the long radicles of this plant are reputed useful in restraining excessive mucous discharges. Hydrophobia has also been treated with it. The root contains sugar, starch, and tannin, and when recent an essential oil, probably that common to other species of Spiraea, and salicylic aldehyde, for the latter is known to be present in the branches and leaves of this plant.
Spiraea Aruncus, Linné.—Europe and United States. A perennial herb, with slender racemes of many, small white blossoms. The herb has an aromatic, bitterish, astringent taste, and the odor is pleasant. The flowers, upon distillation with water, yield salicylic aldehyde, while, the herb yields none, but produces hydrocyanic acid. (For further details, see Gildemeister and Hoffmann, loc. cit.: also see Amer. Jour. Pharm., 1892, p. 306.)