This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
Lappa. - Synonym. - Burdock. The root of Arctium Lappa Linne and some other species of Arctium (nat. ord. Compositae).
Europe and Northern Asia; naturalized in North America, in waste places.
About 30 cm. or more long, and in its thickest portion, from I to 2 cm. thick; nearly simple, fusiform, fleshy, longitudinally wrinkled, crowned with a tuft of whitish, soft, hairy leaf-stalks; grayish-brown, internally paler; fracture somewhat horny; bark rather thick, the inner part and the wood radially striate, the parenchyma free from starch, - often with cavi ties lined with white remains of tissue; odor feeble and unpleasant; taste mucilaginous, sweetish and somewhat bitter.
Dose, 1/2 to 1 dr.; 2. to 4. gm.
Burdock is considered to be a diuretic and a diaphoretic alterative. It has been recommended in the treatment of various chronic skin diseases, especially in psoriasis and acne.