This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The common barberry, Berberis vulgaris, Linne (N.O. Berberideae), is a shrub about 2 metres high, with three-lobed thorns at the bases of the tufts of leaves. It occurs scattered over Great Britain, and over the greater part of Europe and temperate Asia. The yellow flowers, in elegant drooping racemes, are succeeded by oblong scarlet fruits.
Small, thin, nearly flat pieces not often exceeding 5 cm. in length or 1 cm. in breadth, dark in colour, with a decided yellow or yellowish grey tinge. The outer layer (cork) is dark yellowish grey, and marked with shallow, longitudinal furrows or deeper fissures, becoming ultimately scaly; it frequently bears the minute black apothecia of small inconspicuous lichens. The inner surface is dark yellowish brown, longitudinally striated and fibrous, and occasionally has fragments of yellow wood adhering to it. The fracture is short in the outer portion (cork and cortex), but fibrous and strongly laminated in the inner (bast). The transverse section exhibits under the lens a narrow cork and a dark brown bast traversed by paler, yellow medullary rays. The bast rays contain narrow, tangentially elongated bundles of bast fibres, which easily separate from the bast parenchyma in strands and produce the laminated appearance and fracture. The bark has a bitter taste, and colours the saliva yellow.
Barberry bark contains several alkaloids, of which berberine is the most important.
Oxyacanthine and berbamine are colourless alkaloids that have been obtained from the bark of barberry root, and doubtless exist also in that of the stem.
Berberine, C20H19NO5, crystallises in brilliant yellow needles with four or six molecules of water, and melts when anhydrous at 145°; it forms well crystallised compounds with acetone and chloroform, and is coloured in aqueous solution blood-red by chlorine water. Berberine is one of the few alkaloids that occur in plants belonging to several different natural orders (Berberideoe, Ranun-culaceoe, Rutaceoe, Leguminosoe).
Barberry bark is sometimes employed as a remedy for fevers, and as a tonic.