Taraxacum. U. S. (Br.)

Botanical name: 

Taraxacum. U. S. (Br.)

Taraxacum. Tarax. [Dandelion].

"The dried rhizome and roots of Taraxacum officinale Weber (Fam. Compositae). Preserve the thoroughly dried drug in tightly-closed containers, adding a few drops of chloroform or carbon tetrachloride, from time to time, to prevent attack by insects." U. S. "Taraxacum Root is the fresh root of Taraxacum officinale, Wiggers. Collected in the autumn." Br.

Taraxaci Radix, Br., Taraxacum Root; Dandelion Root, Blowball, Milk, Witch, or Yellow Gowan, Lion's-tooth, Cankerwort; Pissenlit, Dent de Lion, Fr. Cod.; Radix Taraxaci cum herba, P. G.; Löwenzahn, G.; Tarassaco, It.; Taraxacon, Diente de Leon, Sp.

The dandelion is an herbaceous plant, with a perennial fusiform root. The leaves, which spring immediately from the short upright rhizome, are long, pinnatifid, generally runcinate, with the divisions toothed, smooth, and of a fine 'green color. The common name of the plant was derived from the fancied resemblance of its leaves to the teeth of a lion. The flower-stem rises from the midst of the leaves, six inches or more in height. It is erect, simple, naked, smooth, hollow, fragile, and terminated by a large golden-colored flower, which closes in the evening and expands with the returning light of the sun. The involucre is smooth and double, with the outer scales bent downward. The florets are very numerous, ligulate, and toothed at their extremities. The receptacle is flat and naked. The pappus is stipulate, and at the period of maturity is disposed in a spherical form, and is so light and feathery as to be easily borne away by the wind, with the achene attached. Another plant resembling the common dandelion, the achenes of which, however, are narrower and bright red or reddish brown, known as the red-seeded dandelion, is the product of T. erythrospermum, Andrz., and is supposed by some to be naturalized from Europe.

The common dandelion, Taraxacum officinale, grows spontaneously in widely separated parts of the globe. It is abundant in this country, adorning our grass plots and pasture grounds with its bright yellow flowers, which, in moist places, show themselves with the first opening of spring, and continue to appear until near the close of summer. In India the plant is cultivated in various parts of the country, and its root collected for use between the months of September and February. (P. J., Dec. 1871, 523.) All parts of the plant contain a milky bitterish juice, which exudes when they are broken or wounded. The leaves, when very young and blanched by the absence of light during their growth, are tender and not unpleasant to the taste, and are sometimes used as a salad. When older and of their natural color, they are medicinal, but the leaves of the wild plant in various stages of its early growth are used for salads by those who have cultivated a taste for this vegetable. The Pharmacopoeias recognize only the root. It should be full grown when collected, and should be employed in the recent state, as it is then most active. It does not, however, as stated by Duncan, lose nearly all its bitterness by drying, and the root dug up in the warmer seasons might, if dried with care, be employed with propriety in the succeeding winter. The juice of the root is thin and watery in the spring; milky, bitter, and spontaneously coagulable in the latter part of summer and autumn, and sweet and less bitter in the winter when affected by the frost. The months of July, August, and September are, therefore, the proper periods for collecting it.

Henry Barton, of Brighton, England, prepared the juice from the flower-stalks by crushing and pressure, adding 25 per cent. of spirit, and, after allowing it to stand for some weeks in glass bottles, filtering to separate a very small quantity of deposit, and setting aside for use. According to Barton, it remains bright, and retains its characteristic taste. Though not so rich in solid constituents as the juice of the root, yet, having an equal bitterness, it is probably not less efficacious as a medicine, if it be true, as stated by Bentley, that the efficacy of the medicine does not depend solely on the amount of its solid constituents, but principally if not entirely on the bitter principle it contains. Barton stated that the juice is certainly one of the best preparations of taraxacum. (A. J. P., 1872, p. 509.)

Properties.—The official description of Taraxacum follows: "Cylindrical or somewhat flattened, gradually tapering, usually in broken pieces, from 6 to 15 cm. in length and from 5 to 15 mm. in thickness; externally brown or blackish-brown, longitudinally wrinkled, having numerous root and rootlet-scars; crown simple or branched with numerous leaf-bases showing annulate markings; odor slight or inodorous; taste bitter. Under the microscope, transverse sections of the root of Taraxacum show a porous, pale yellow wood from 1 to 4 mm. in diameter, surrounded by a light brown bark from 2 to 6 mm. in thickness, the latter composed of concentric layers of lacticiferous vessels and sieve tissues, alternating with whitish inulin-bearing parenchyma. The rhizome portions show a small pith. The powder is light brown; when examined under the microscope it exhibits parenchyma cells which are large, thin-walled and contain irregular masses of inulin; fragments with yellowish-brown lacticiferous vessels; trachea; reticulate; intermediate fibers non-lignified, with irregular, simple and oblique pores. Taraxacum yields not more than 10 per cent. of ash." U. S. "Fresh root frequently three decimetres or more long, and twelve millimetres or more thick, smooth and yellowish-brown externally, whitish within. Fracture short, the exposed surface showing a small yellow porous wood, surrounded by a thick nearly white cortex exhibiting a variable number of irregular concentric rings, from which a milky juice exudes. Inodorous; taste bitter." Br.

Taraxacum should be free from the root of Cichorium Intybus Linné, which closely resembles it, but is usually paler, more bitter, and has the milk vessels in radiating lines. The drug consists in part of the rhizome which shows from ten to fifteen fibro-vascular bundles surrounded by the parenchyma-tissue of the pith, the diameter of which in some instances exceeds the thickness of the woody zone several times. In other respects the structure of the rhizome resembles the root, the concentric' arrangement of the lacticiferous ducts in particular excluding any possibility of mistaking the specimens for chicory, etc. (Am. Drug., 1887, p. 2.) The active properties of taraxacum are yielded to water by boiling, and do not appear to be injured in the process. Dragendorff obtained from the root gathered in October and dried at 100° C. (212° F.) 24 per cent. of inulin and some sugar. The root gathered in March from the same place yielded 1.74 per cent. of inulin, 17 of uncrystallizable sugar, and 18.7 of levulin. This last-named substance, discovered by Dragendorff, has the same composition as inulin, but dissolves in cold water, and is devoid of any rotatory power. Mannite, which has been found in the infusion of the root, has been demonstrated by Smith, of Edinburgh, not to pre-exist in the root, but to be formed by spontaneous changes consequent on exposure.

A crystallizable principle has been extracted from the juice of the root by Pollex, who has named it taraxacin. It is bitter and somewhat acrid, fusible, but not volatile, sparingly soluble in cold water, but very soluble in boiling water, alcohol, and ether. It is obtained by boiling the milky juice in distilled water, filtering the concentrated liquor, and allowing it to evaporate spontaneously in a warm place. The taraxacin crystallizes, and may be purified by repeated solution and crystallization in alcohol or water. Kromayer (A. Pharm. (2), cv, 6) also obtained taraxacin, and, in addition, a second crystalline principle, taraxacerin, C8H16O, insoluble in water, but soluble in alcohol. According to Vogel, the infra-cellular substance of the root consists chiefly of pectose, which is the result of a metamorphosis of the substance constituting the membrane of the cells. L. E. Sayre found that the yield of taraxacin varies in roots collected at different seasons. (See Proc. A. Ph. A., 1893, 1894, 1895, 1896,1897.)

F. B. Power (C. D., 1912, p. 822) contributed the results of some investigations of this drug, in which he states that besides inulin, resin and sugar, no definite substances have previously been isolated. The taraxacin of Polex (1839), and the taraxacerin of Kromayer (1861), to which was assigned the formula C40H80O5_ are both alleged to be definite mixtures. Power found in the air dried English root, an enzyme, essential oil, oily resin, fatty acids, including melissic, and p-hydroxy-phenylacetic acid, which had never before been isolated from a plant.

The roots of various plants have been largely substituted for dandelion in England and on the Continent by the herb gatherers, and we are informed that fraudulent substitution is not unfrequent, in this country, of the root of Cichorium Intybus, or chicory. It is rare to find chicory mixed with dandelion, the former being usually boldly substituted for the latter.

Uses.—Taraxacum was formerly supposed to possess cholagogic as well as diuretic powers. It has been used in various conditions accompanied with congested or torpid liver. There is, however, no sufficient reason for believing it possesses any therapeutic virtues. The dried root is sometimes mixed, in powder, with ground coffee, the taste of which covers that of the dandelion. It is roasted and powdered and then prepared in the same manner.

Dose, one to three drachms (3.9-11.6 Gm.).

Off. Prep.—Fluidextractum Taraxaci, U. S. (Br.); Extractum Taraxaci, U. S; Br.; Succus Taraxaci, Br.; Elixir Gentianae Glycerinatum, N. F.; Elixir Taraxaci Compositum, N. F.

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.