Leptandra. Veronica virginica. Culver's Root, Culver's Physic, Black Root.
Related entry: Veronica
Leptandra. N. F. IV [U. S. P. VIII). Culver's Root. Culver's Physic. Black Root. Racine de Leptandra, ou de Veronique de Virginie, Fr. Leptandra-Wurssel, G.—"The dried rhizome and roots of Veronica virginica Linné (Fam. Scrophulariaceae), without the presence of more than 5 per cent. of stems or other foreign matter." N. F. Veronica virginica, commonly called Culver's root, or Culver's physic, is an herbaceous perennial, with a simple, erect stem, three or four feet high, smooth or downy, furnished with leaves in whorls, and terminating in a long spike of white flowers. The leaves, of which there are from four to seven in each whorl, are lanceolate, pointed, and minutely serrate, and stand on short foot-stalks. A variety was seen by Pursh with purple flowers, which was described and figured as a distinct species by Rafinesque, under the name of L. purpurea. The plant flowers in July and August. It grows throughout the United States east of the Mississippi, affecting mountain meadows in the South and rich woods in the North, and is not unfrequently cultivated. The National Formulary describes leptandra as follows "Rhizome usually of horizontal growth, nearly cylindrical, somewhat branched; branches readily separable from the main rhizome, from 4 to 10 cm. in length and from 4 to 13 mm. in diameter; externally grayish-brown to dark reddish-brown, annulate from circular scars of bud-scales, upper surface with short stem remnants, occasionally with buds, and numerous circular stem-scars; from the under and lateral portions arise numerous coarse roots; fracture very tough and woody; internally, bark rather thin, dark brown and resinous, wood about the same thickness as the bark, light brown and porous, pith large, more or less hollow, the color being similar to that of the bark. Roots from 1 to 10 cm. in length and from 1 to 2 mm. in diameter; externally dark brown to purplish-brown, smooth and faintly longitudinally wrinkled; fracture short; internally with a thick, brownish-black bark and small, light brown central cylinder. Nearly odorless; taste very bitter and acrid.
"The powder is brown to yellowish-brown; odor strong, penetrating; consisting of numerous irregular fragments, many of them being colored pink or violet upon the addition of hydrated chloral T.S.; starch grains numerous, mostly in the parenchymatous cells, the individual grains nearly spherical or more or less polygonal, and from 0.002 to 0.008 mm. in diameter; tracheae with spiral thickenings or with simple or bordered pores; wood fibers with thick lignified walls, with simple pores or with bordered pores, resembling tracheids; fragments of parenchyma containing a light brown or brownish-black resin, the latter frequently closely coherent with the starch grains in the cells thus preventing the separation of the individual starch grains; mounted in hydrated chloral T.S., occasional elongated cells with a lemon yellow, oily substance are observed. Leptandra yields not more than 12 per cent. of ash." N. F. For a microscopical description of leptandra, by A. P. Breithaupt, see A. J. P., 1897, 235.
Water and alcohol extract the virtues of the root. According to E. S. Wayne, of Cincinnati, it contains a peculiar crystalline principle, leptandrin, to which the virtues of the medicine may be ascribed. F. F. Mayer confirmed the presence of the crystalline principle, and classed it as a glucoside, but Power and Rogerson (Tr. Chem. Soc., 1910, xcvi) were unable to find any such principle. The resinous matter obtained by making a tincture of the root and precipitating this with water has been improperly called leptandrin, and considered the active principle. Subsequently Wayne obtained from the root a saccharine principle having the properties of mannite. (A. J. P., 1859, p. 557.) G. Steinmann (A. J. P., 1887, p. 229) obtained pale lemon-yellow crystals of a peculiar agreeable odor and a very bitter taste. They were not precipitated from solution by Mayer's reagent or by tannin, and did not yield glucose on being boiled with diluted sulphuric acid.
The recent root is said to act violently as a cathartic, and sometimes as an emetic. In the dried state it is much milder, but less certain. The practitioners calling themselves eclectics consider it an excellent cholagogue, and use both the impure resin, which they call leptandrin, and the root itself as a substitute for mercurials. Rutherford, in his experiments upon dogs, found leptandrin to act rather feebly upon the liver. The powdered extract and fluidextract are recognized by the N. F. (see Part III). Dose, fifteen to sixty grains (1-3.9 Gm.); of the impure resin, two to four grains (0.13-0.26 Gm.).