Encyclopædia Britannica, Ninth Edition/Taraxacum

TARAXACUM is the name usually applied in medical practice to the common dandelion (Taraxacum officinale, Wiggers). The Dandelion (q.v.) is a plant of the northern hemisphere, extending to the Arctic regions, and is cultivated in India. The preparations chiefly employed are the fluid extract, the preserved juice of the root, or succus, and the solid extract. The dried and roasted root, mixed with ground coffee, is often sold under the name of dandelion coffee for use as a beverage. The root is most bitter from March to July, but the milky juice it contains is less abundant in the summer than in the autumn. For this reason, the extract and succus are usually prepared during the months of September and October. After a frost a change takes place in the root, which loses its bitterness to a large extent. In the dried state the root will not keep well, being quickly attacked by insects. Externally it is brown and wrinkled, internally white, with a yellow centre and concentric paler rings. It is 2 inches to a foot long, and about to 1/4 to 1/2 inch in diameter. The juice when first exuded is bitter and neutral, but on exposure to the air soon acquires an acid reaction and a brown tint, coagulating and depositing a complex substance, to which the name of “leontodonium’’ has been given. From this deposit a bitter principle, "taraxacin," and an acrid crystalline substance, "taraxacerin," soluble in alcohol, have been obtained, but to which of these the medicinal properties are due is not known. In autumn the root contains about 24 per cent, of inulin, but in summer barely 2 per cent. When the juice has fermented, mannite is found in it. Taraxacum is chiefly employed as a stimulant tonic in hepatic disorders. In some cases it acts as a cholagogue and mild aperient, and in others as a diuretic.

The roots of other Composite plants are sometimes gathered by careless collectors for dandelion, especially that of Leontodon hispidus (L.). The root of this plant is tough when fresh, and rarely exudes any milky juice. The flowers, moreover, have feathery pappus, while in the dandelion it is simple.