Riverbank-dogbane (A. Album Greene), which frequents the banks of rivers and similar moist locations from Maine to Wisconsin, Virginia and Missouri. This plant is perfectly smooth and has white flowers and relatively smaller leaves than A. cannabinum.
Velvet dogbane (A. pubescens R. Br.), which is common from Virginia to Illinois, Iowa and Missouri. The entire plant has a soft, hairy or velvety appearance, which renders identification easy. According to the latest edition of the National Standard Dispensatory it is not unlikely that this is the plant that furnishes the drug that has been so favorably reported upon.
Apocynum androsaemifolium is also gathered by drug collectors for Apocynum cannabinum. Its root is likewise employed in medicine, but its action is not the same as that of cannabinum and it should therefore not be substituted for it. It closely resembles cannabinum.
Description of Rootstock — The following description of the drug as found in commerce is taken from the United States Pharmacopoeia: "Of varying length, 3 to 8 mm. thick, cylindrical or with a few angles produced by drying, lightly wrinkled, longitudinally and usually more or less fissured transversely; orange-brown, becoming gray-brown on keeping; brittle; fracture sharply transverse, exhibiting a thin brown layer of cork, the remainder of the bark nearly as thick as the radius of the wood, white or sometimes pinkish, starchy, containing laticiferous ducts; the wood yellowish, having several rings, finely radiate and very coarsely porous; almost inodorous, the taste starchy, afterwards becoming bitter and somewhat acrid."
Collection, Prices and Uses — The root of black Indian hemp is collected in autumn and brings from 8 to 10 cents a pound.
It is official in the United States Pharmacopoeia and has emetic, cathartic, diaphoretic, expectorant and diuretic properties, and on account of the last-named action it is used in dropsical affections.
The tough, fibrous bark of the stalks of Black Indian Hemp was employed by the Indians as a substitute for hemp in making twine, fishing nets, etc.
Chamaelirium, or Helonias.
Chamaelirium Luteum (L.) A. Gray.
Synonym — Helonias Dioica Pursh.
Other Common Names — Unicorn root, false unicorn-root, blazing star, drooping starwort, starwort, devil's-bit, unicorn's-horn.