Uses—Taraxacum is much employed as a mild laxative and tonic, especially in hepatic disorders.
Adulteration—The roots of Leontodon hispidus L. (Common Hawkbit) have occasionally been supplied by fraudulent herb-gatherers in place of dandelion. Both plants have runcinate leaves, but those of hawkbit are hairy, while those of dandelion are smooth. The (fresh) root of the former is tough, breaking with difficulty and rarely exuding any milky juice.[1451]
The dried root of dandelion is exceedingly liable to the attacks of maggots, and should not be kept beyond one season.
HERBA LACTUCÆ VIROSÆ.
Prickly Lettuce; F. Laitue vireuse; G. Giftlattich.
Botanical Origin—Lactuca virosa L.,[1452] a tall herb occurring on stony ground, banks and roadsides, throughout Western, Central and Southern Europe. It is abundant in the Spanish Peninsula and in France, but in Britain is only thinly scattered, reaching its northern limit in the south-eastern Highlands of Scotland.
History—The introduction of this lettuce into modern medicine is due to Collin (the celebrated physician of Vienna, mentioned in our article on Rad. Arnicæ, [p. 390]), who about the year 1771 recommended the inspissated juice in the treatment of dropsy. In long standing cases, this extract was given to the extent of half an ounce a day.
The College of Physicians of Edinburgh inserted Lactuca virosa L. in their pharmacopœia of 1792, while in England its place was taken by the Garden Lettuce, L. sativa L. The Authors of the British Pharmacopœia of 1867 have discarded the latter, and directed that Extractum Lactucæ shall be prepared by inspissating the juice of L. virosa.
Description—The plant is biennial, producing in its first year depressed obovate undivided leaves, and in its second a solitary upright stem, 3 to 5 feet high, bearing a pinacle of small, pale yellow flowers, resembling those of the Garden Lettuce. The stem, which is cylindrical and a little prickly below, has scattered leaves growing horizontally; they are of a glaucous green, ovate-oblong, often somewhat lobed, auricled, clasping, with the margin provided with irregular spinescent teeth, and midrib white and prickly. The whole plant abounds in a bitter, milky juice of strong, unpleasant, opiate smell.
Chemical Composition—We are not aware of any modern chemical examination having been made of Lactuca virosa. The more important constituents of the plant are those found in Lactucarium, to the article on which the reader is referred.