The rhizome of Osmunda regalis, Michaux (Osmunda spectabilis, Willdenow).
COMMON NAMES: Buckhorn brake, Royal flowering fern.
Botanical Source.—This fern has a hard, scaly, tuberous rhizome, beset with numerous fibers, and having a whitish core in the center. The fronds are several, erect, 3 or 4 feet high, doubly pinnate, smooth, bright green; primary divisions or pinnae from 6 to 10, nearly opposite, remote, and hardly a span long. The leaflets are more numerous, often alternate, sessile or nearly so, oblong, bluntish, entire or obscurely-crenate, with 1 rib, and numerous transverse veins; base dilated, heart-shaped, or somewhat lobed. Some of the upper leaflets are cut, and as it were, partially transmuted, into dense clusters or spikes of innumerable, small, light-brown, veiny, globular, 2-valved thecae, entirely covering the segments; several of the upper divisions of the leaf consisting entirely of such thecae, composing a compound panicle. Spores green (L.—W.—G.).
History and Description.—This beautiful fern is found in meadows and low moist grounds, throughout the United States, flowering in June. The main root or caudex is the medicinal part; it is about 2 inches long, and has the shape of a buck's horn. It is composed of a number of layers or scales, which are elongated, imbricated, with satiny, translucent margins, and throws out a mass of entangled, delicate radicles. It contains an abundance of mucilage, which is extracted by boiling water. The ash of osmunda consists, to about 50 per cent, of silica. The roots should be collected in August, or about the latter part of May, and dried with great care, as they are apt to become moldy.
The Osmunda cinnamomea, or Cinnamon-colored fern, is inferior to the preceding, but is frequently used for the same purposes. Its root is similar, but much larger, and when its stems are young, during the spring months, they present a white or cinnamon-colored, pubescent appearance, with the leaves circinate and downy.
Action, Medical Uses, and Dosage.—Mucilaginous, tonic, and styptic. Used in chronic coughs with profuse perspiration, diarrhoea, and dysentery; also as a tonic during convalescence from exhausting diseases. One root, infused in a pint of hot water for half an hour, will convert the whole into a thick jelly. Very valuable in leucorrhoea, and other female weaknesses, and said to be an almost certain cure for rickets, in doses of 3 drachms of the root, 3 times a day. The mucilage mixed with brandy is a popular remedy as an external application for subluxations and debility of the muscles of the back. For internal use, the roots may be infused in hot water, sweetened, and ginger, cinnamon, brandy, etc., added, if not contraindicated.