Acaciae Cortex. Br. Acacia Bark.
Preparation: Decoction of Acacia Bark
"Acacia Bark is the dried bark of Acacia arabica, Willd., and also the dried bark of Acacia decurrens, Willd.; obtained from wild or cultivated trees not less than seven years old, and, after being dried, kept for one year before use." Br.
Wattle Bark; Black Wattle; Babul Bark; Neb-neb.
The Acacias are known not only for their gums, but a number of them contain large quantities of tannin and hence are used in tanning. Among the latter are the so-called wattle barks of Australia, and also catechu. The chief of the Australian trees is the black wattle (A. decurrens), the bark of which yields from 24 to 42 per cent. of tannin, and is employed as an astringent. More recently A. arabica has been similarly used in East Africa.
Characters.—"Bark of A. arabica hard and woody, rusty brown, and tending to divide into several layers. Outer surface of the older pieces covered with thick blackish periderm, rugged, fissured longitudinally and transversely. Inner surface red, longitudinally striated and fibrous. Taste astringent and mucilaginous."
"Bark of A. decurrens usually in curved or channelled pieces, 1.5 to 3 mm. thick. External surface greyish-brown, darkening with age; often with irregular longitudinal ridges, and, sometimes, transverse cracks. Inner surface reddish-brown, longitudinally striated; fracture irregular and coarsely fibrous, freshly fractured surface pale. Slight tan-like odor; taste astringent." Br.
Acacia bark owes its medicinal properties to the tannin it contains. It is used as an astringent in diarrheas, being usually employed in the form of a decoction (1:16), in doses of one-half to two fluidounces (15-60 mils).