This section of the book is from "The Complete Herbalist" by Dr. O. Phelps Brown. Also available from Amazon: The Complete Herbalist: The People Their Own Physicians By The Use Of Nature's Remedies.
COMMON NAMES. Twin-leaf, Ground-Squirrel Pea.
MEDICINAL PART. The root.
Description. -- This plant is perennial, and has a horizontal rhizoma or fleshy root, with matted fibrous radicles. The stem is simple, naked, one-flowered, and from eight to fourteen inches in height. The leaves are in pairs, broader than long, ending in an obtuse point, smooth and petioled; flowers, large and white; and fruit an obovate capsule.
History. -- This plant is found from New York to Maryland and Virginia, and in many parts of the Western States. It grows chiefly in limestone soil, but also is found in woods and near rivers, irrespective of limestone, and flowers in April and May. The root is the part used, and its virtues are extracted by water or alcohol. A chemical analysis of this plant showed it to contain tannic acid, gum, starch, pectin, fatty resin, bitter matter, similar to polygalic acid, carbonate and sulphate of potassa, lime, iron, magnesia, silica, etc.
Properties and Uses. -- It is diuretic, alterative, antispasmodic, and a stimulating diaphoretic. It is successfully used in chronic rheumatism, secondary or mercurio-syphilia, dropsy, in many nervous affections, spasms, cramps, nervous excitability, etc. As a gargle it is useful in diseases of the throat.
Dose. -- Of the decoction, from two to four fluid ounces, three or four times a day. Of the saturated tincture, from one to three fluid drachms, three times a day.