Botanical Source.—Viola pedata, Blue violet, or, as it is sometimes called, Bird's-foot violet, is an indigenous, stemless plant, glabrous, with the leaves and scapes all from perennial, fleshy, premorse, subterranean root-stocks. The leaves are pedately 5 to 9-parted; the lobes, linear-lanceolate, obtuse, and nearly entire. The petioles are armed with long, ciliate stipules at base. Flowers large, very showy, 1 inch broad, pale or deep lilac-purple, and fragrant. The peduncles are somewhat 4-sided, and much longer than the leaves. Segments of the calyx are linear, acute-ciliate, and emarginate behind. Petals veinless, entire and beardless. Spur or beak obscure. Stigma large, flattened at the sides, obliquely truncate, and pierced at the top (W.—G.). Viola odorata is a small, creeping plant, with flagelliform runners; its leaves are roundish-cordate; sepals 5, ovate and obtuse; petals 5; spur very blunt. Its flowers are fragrant, deep-purple, often white, occasionally lilac, and borne on radical, furrowed, quadrangular peduncles. The bracts are inserted above the middle of the scape. Capsules turgid, hairy, bursting with elasticity, many-seeded, and 3-valved. Seeds turbinate and pale (L.—De Candolle).
History and Description.—The Blue violet is common to the United States, growing from Maine to Florida, and west to Missouri, in dry woods and pastures, and sandy places, flowering in May and June. Occasionally a second flowering occurs in August and September. The herb and root are used, and impart their virtues to water. The taste of the flowers is sweet and mucilaginous; of the rhizome, bitter, mucilaginous, and sub-acrid. The Viola odorata, or Sweet violet, of Europe, is much cultivated in this country on account of its beautiful, flowers, which appear in April and May. The flowers of this species are made into a syrup which is official in the French Codex. Of fresh violet petals (the deep-blue ones only, deprived of the calyx), take 10 parts, and boiling water, 20 parts. Infuse, and add to 21 parts of infusion 38 parts of sugar. Both of these plants possess similar properties; the flowers are commonly employed, but the whole plant is medicinal. The flowers should be gathered as soon as they are fully expanded, the sepals removed, and then carefully dried. According to P. L. Simmonds (Amer. Jour. Pharm., 1891, p. 201), the whole plant of Viola odorata is sold in a dry state in all the bazars of Bengal, and is given in infusion as a diaphoretic in fevers. In large doses it nauseates and often produces vomiting. The Romans had a wine of violet flowers, and it is said they are still used in the preparation of sherbets.
Chemical Composition.—The root, leaves and seeds of these odoriferous plants are emetic in larger doses. Boullay (1828) found the whole plant of V. odorata to contain an acrid and poisonous principle which he called violine. It resembles emetine in its action, is a pale-yellow or white powder of bitter and acrid taste, more soluble in water than emetine, insoluble in ether, quite soluble in alcohol, and forming an insoluble compound with tannin solution. It also exists in other plants of this family, particularly in the rhizomes of the perennial, and especially the stemless species of violet. It is not present, however, in the pansy (see below). The root also contains starch, yellow coloring matter, gum, traces of volatile oil, etc. The flowers contain a blue coloring matter, turning green with alkalies. As to the odoriferous principle of the violet, it has not yet been definitely established whether it is identical with the synthetical violet perfume from orris root. (Regarding the latter, see Henry Kraemer, Amer. Jour. Pharm., 1895, pp. 346-356.) K. Mandelin (Dissert., 1881; see Amer. Jour. Pharm., 1882, p. 11) found the leaves of V. odorata to contain a substance which, after boiling, yielded salicylic acid (also see Related Species, below). Boiling water extracts the virtues of these plants.
Action, Medical Uses, and Dosage.—The flowers and seeds of V. odorata act as laxatives in doses of 3 or 4 drachms, rubbed up with sugar and water; the root in 1/2 or 1-drachm doses is emeto-cathartic, but it is uncertain in its action. The odorous emanations from the flowers have caused faintness and giddiness, and in one case were supposed to have brought on apoplexy. The seeds have been recommended in uric acid gravel. Blue violet is mucilaginous, emollient, and slightly laxative; also antisyphilitic and useful, when combined with Corydalis formosa, in syphilis. Has been used in pectoral, nephritic and cutaneous affections, especially crusta lactea. The plant should be used when fresh, as drying destroys its active properties. Prof. Scudder says of it that "it stimulates waste and secretion, relieves nervous irritability, and improves nutrition"—(Spec. Med.). The V. tricolor, or pansy, may be used as a substitute. The roots of these plants are bitterish and slightly acrid, and in doses of from 8 to 10 grains are tonic; from 25 to 30 grains, purgative; and from 40 to 60 grains, emetic.
Related Species.—Viola tricolor, Linné (Herba jacae); Heartsease, Johnny jump-up, Pansy. The wild-growing species of pansy is official in the German Pharmacopoeia, and its variety arvensis in the French Codex. Its corolla has the 3 colors-blue, yellow, and purple. According to Boullay (1828), no emetic violine (see above) is present, but a yellow coloring principle, and an abundance of mucilage was found. The yellow principle has since been shown by Mandelin (Pharm. Zeitschrift für Russland, 1883, p. 329) to be a glucosid violaquercitrin (C42H42O24). From hot solution it forms fine yellow acicular crystals, soluble in alkalies and reprecipitated by acids; when boiled with diluted acids it is split into quercetin, glucose, and a fluorescent body. Previously (1881), Mandelin obtained free salicylic acid from the dried herb, varying from 0.06 to 0.14 percent. It occurs in several other species of Viola. Griffith and Conrad (1884) found 0.13 per cent in the leaves, 0.08 per cent in the stems, and 0.05 per cent in the root; the flowers contained but a trace. The fresh leaf-buds, when rubbed between the fingers, exhibit a distinct odor of methyl salicylate (see monograph on Viola tricolor, by Henry Kraemer, Dissert., Marburg, 1897). The immoderate use of Viola tricolor is said to derange the gastro-intestinal functions, and to induce diuresis, sweating, and a pustular skin eruption. It imparts to the urine a feline odor. Its chief use is as a remedy for the moist eczematous eruptions which are prone to occur on the scalp and face of children. From 5 to 10 drops of a strong tincture may be added to 4 fluid ounces of water, the dose of the mixture being a teaspoonful every 4 hours. In Europe it is used as a blood purifier, and in catarrhal affections of the bronchiae and intestines.
Viola sagittata, Aiton, var. ovata, or Rattlesnake violet, has been highly recommended in the bites of rattlesnakes, the infusion to be freely administered; and the infusion used internally, with a fomentation of the leaves locally applied, has proved efficient in obstinate chronic ophthalmia; a similar course is reputed very valuable in scrofulous diseases. Probably all the species possess analogous properties; they are undoubtedly more active agents than are generally supposed and deserve further investigation.
Anchietaea salutaris, St. Hilaire (Noisettia pyrifolia, Martius).—A Brazilian shrub, the root of which is emeto-cathartic. Sugar, starch, gum, tannin, resin, and a pale-yellow, crystalline basic anchietine (0.40 per cent) were found in the root by Peckolt in 1859 (Archiv der Pharm., Vol. CXLVII, p. 271). The base has a nauseous, persistently pungent taste, is freely soluble in alcohol, sparingly in boiling water; insoluble in ether; forms a characteristic hydrochloride, and produces violet, subsequently turning to black, with sulphuric acid. From the fact that this root will salivate, it has been used in powder and alcoholic tinctures for the relief of cutaneous disorders and syphilis.
Ionidium Marcucci, Bancroft (Ionidium parviflorum, Ventenat), South America, near Mount Chimborazo.—The cuichunchulli of the Indians, much used in South America in cutaneous disorders, and said to be peculiarly efficient in elephantiasis. Small doses of the root are diaphoretic, sialagogue, and diuretic, while large doses prove emetic and purgative.
Ionidium Ipecacuanha, Ventenat.—A Brazilian root, used as a substitute for ipecacuanha (see Ipecacuanha). It contains an emetic alkaloid not identical with emetine or violine (see J. B. Barnes, Pharm. Jour. Trans., Vol. XV, 1884-85, p. 515).
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.