Botanical Source and History.—This is a little plant about 6 or 8 inches high, common in open woods throughout the middle and eastern United States. The root consists of a cluster of oblong tubers, bearing a few radical biternate leaves, and a flowering stem. The cauline leaves are clustered in a whorl at the top of the stem, forming an involucre at the base of the flowers. The flowers, which are centrifugal in development, have from 8 to 10 colored sepals, varying in color from a pale-pink to a pure white. This pretty little plant is one of the earliest spring flowers, blooming in March and April. It has been the subject of considerable diversity of opinion among botanists, concerning its position in the Natural System, being intermediate in character between the two genera, Anemone and Thalictrum; with the flower of the former, it has the fruit of the latter, and while the arrangement of the leaves is like that of the genus Anemone, their shape accords with that of the different species of Thalictrum. Linnaeus, who was the first to give the plant a specific name, called it "Anemone thalictroides," which name it retained until Michaux transferred it to the genus Thalictrum under the name Thalictrum anemonoides. This change was accepted by De Candolle, and is now adopted by Gray and Bentham and Hooker. Pursh described a 1-flowered variety, but it is not generally considered distinct. Nothing is known of the chemical composition of any part of this plant.
Thalictrum flavus, Linné, and Thalictrum majus, Europe, are known in England as Poor man's rhubarb. From the root of Thalictrum macrocorpum, a plant growing in the Pyrenees, a neutral, crystallizable, yellow body, macrocarpin, and a crystallizable, white alkaloid, thalictrine, resembling aconitine, have been obtained by Hanriot and Doassans (Amer. Jour. Pharm., 1881, p. 336).
Action, Medical Uses, and Dosage.—But little is known concerning the therapeutical properties of this plant. Dr. S. E. Barber, of Connsville, Mo., informs us that he has found it to be a valuable remedy in external and internal hemorrhoids, not accompanied with hemorrhage. The method of using it is to simply eat 3 or 4 of the small root-tubers, 3 times a day. We used some of the tubers, which he sent to us, in two cases of blind piles, and with apparent success. If further and more extensive trial of these tubers should confirm these conclusions as to their efficacy, it is probable that a fluid preparation could be made from them, possessing the same properties, and in a more convenient form (J. King).
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.