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.
MEDICINAL PART. Bark and berries.
Description. -- Barberry is an erect, deciduous shrub, from three to eight feet high, with leaves of an obovate-oval form, terminated by soft bristles, about two inches long, and one-third as wide. The flowers are small and yellow, in clusters, and the fruit bright-red oblong berries, in branches, and very acid.
History. -- This shrub is found in the New England States, on the mountains of Pennsylvania and Virginia, among rocks and hard gravelly soil. Occasionally it is found in the West on rich grounds. It flowers in April and May, and ripens its fruit in June. Its active principle is Berberina.
Properties and Uses. -- It is tonic and laxative, indicated in jaundice, chronic diarrhoea, and dysentery. The berries form an agreeable acidulous draught, useful as a refrigerant in fevers; the bark is bitter and astringent, and used in the treatment of jaundice. The bark of the root is the most active; a teaspoonful of the powder will act as a purgative. A decoction of the bark or berries will be found of service as a wash or gargle in aphthous sore mouth and chronic ophthalmia.