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. Culver's Physic, Tall Speedwell.
MEDICINAL PART. The root.
Description. -- It is perennial, with a simple, straight, smooth, herbaceous stem, and grows from three to four or five feet in height. The leaves are short petioled, whorled in fours to sevens, lanceolate, acuminnate, and finely serrated. The flowers are white, nearly sessile, and very numerous. Calyx four-parted corolla small and nearly white; stamens, two. The fruit is a many-seeded capsule.
History. -- This plant is indigenous to the United States, but is to be found in good condition only in limestone countries. It is often discovered in new soil, in moist woods, in swamps, etc., but its medicinal virtues are feeble, excepting when it is found where there is limestone. The root is the part used. It is perennial, irregular, horizontal, woody, and about as thick as the forefinger. It is gathered in the fall of the second year. The fresh root should never be used, as it is very violent and uncertain in its operations. The dried root, after having been properly prepared, is what may be relied upon for beneficial effects. Leptandrin is its active principle.
Properties and Uses. -- The fresh root is too irritant to be used, although a decoction of it may, with care, be used in intermittent fever. The dried root is laxative, cholagogue, and tonic, and very much used in chronic hepatic diseases. It is an excellent laxative in febrile diseases, and peculiarly applicable in billious and typhoid fevers. As a laxative and tonic it is very useful in dyspepsia, especially when associated with torpidity of the liver. In diarrhoea and dysentery, as a cathartic it frequently effects a cure in one active dose. This admirable remedy is one of the ingredients of my "Renovating Pill," see page 469.
Dose. -- Powdered root, twenty to sixty grains; infusion, half an ounce; leptandrin, one-fourth grain to a grain.