Lappa. Burdock Root. Arctium Lappa, Arctium spp.
Lappa. N. F. IV (U. S. P. VIII). Burdock Root. Radix Bardanae. Bassies. Beggars' Buttons. Cuckoo Button. Harebur. Bardane, Fr. Cod. Glouteron, Fr. Klettenwurzel, G. Bardana, It.—" The dried root of Arctium Lappa Linné, or of other species of Arctium (Fam. Compositae), collected from plants of the first year's growth." N.F.
The stem of the burdock is succulent, pubescent, branching, and three or four feet in height, bearing very large, cordate, denticulate leaves, which are green on their upper surface, whitish and downy on the under, and stand on long footstalks. The flowers are purple, with heads globose, and in terminal panicles. The involucre consists of imbricated scales, with hooked extremities, by which they adhere to the clothing of man and the coats of animals. The achemes are oblong, somewhat compressed and three-angled, ribbed, truncate. Although a native of Europe, burdock is abundant in the United States, where it grows on the roadsides, among rubbish, and in cultivated grounds. There are three recognized species of Arctium in North America—viz., A. tomentosum (Lam.) Schk. (Woolly or Cottony Burdock); A. Lappa L. (Burdock, Clotbur or Great Bur); and A. minus Schk. (Common Burdock).
It is described by the N. F. as "nearly simple, fusiform, of variable length from 5 to 20 mm. in diameter near the crown; frequently split or in broken pieces; externally grayish-brown, longitudinally wrinkled, the crown somewhat annulate, sometimes surmounted by a woolly tuft of leaf remains; fracture somewhat horny; a dark cambium separating the thick brownish bark from the yellowish porous and radiate wood, centrally hollow or containing a white, pith-like tissue. Odor slight; taste mucilaginous, sweetish, and slightly bitter. The powder is light brown and, when examined under the microscope, exhibits parenchyma cells of the cortex; the medullary rays and wood containing amorphous masses or sphere-crystals of inulin; yellow resin cells occur in the cortical parenchyma of young roots; wood fibers few; no starch and no calcium oxalate. Lappa yields not more than 6 per cent. of ash." N. F.
Inulin has been found in it by Guibourt, and sugar by Fee, while F. E. Hendershott believes that it contains a glucoside, besides arabin and pectin and extractives. (Proceedings of Mich. Pharm. Assoc., 1887.) Trimble also obtained from the root a bitter, crystalline glucoside. (Ph. Era, 1888, p. 133.) Thos. Donaldson (A. J. P., 1890, p. 123) found 8.6 per cent. of yellow fixed oil and about 1 per cent. of white waxy matter. A small quantity of volatile oil (0.065 per cent.) has been found in burdock root according to Haensel's Report, Oct., 1902. The inulin usually exists in parenchymatous cells in a different state, but if sections of the green root be dehydrated by soaking in 95 per cent. alcohol, the inulin will be found in spheroidal form.
An interesting account of burdock and its use as an edible vegetable in Japan, by Inazo Nitobe, may be found in A. J. P., 1897, 416.
Uses.—Burdock root has been employed as a diuretic and diaphoretic alterative, especially useful in the gouty, scorbutic, and syphilitic and scrofulous diatheses; also in various chronic skin diseases, especially in psoriasis, prurigo, and acne. (M. S. Rep., 1868.) The fresh leaves have been employed both externally and internally in cutaneous eruptions and ulcerations. There is no sufficient reason, however, to believe it has any medicinal virtue. This fluidextract is recognized by the N. F. (see Part III).
Dose, thirty to ninety grains (2.0-5.8 Gm.).