Alder Buckthorn Bark
Three species of the genus Rhamnus (the name derived from the Greek rhamnos, a branch) are possessed of the same medicinal properties in varying degrees. The Common or Purging Buckthorn, a much-branched shrub, usually about 6 feet high, but sometimes as much as 10 or 12 feet, is indigenous to North Africa, the greater part of Europe and North Asia. Though found throughout England in woods and thickets and near brooks, it is practically confined to a calcareous soil, except in a few counties, such as Bucks., Herts., Oxon. and Wilts. In Scotland it occurs only in a single locality. Part Used---The berries are the part used medicinally, collected when ripe and from which an acrid, nauseous, bitter juice is obtained by expression. From this juice, with the addition of sugar and aromatics, syrup of Buckthorn (Succus Rhamni) is prepared. When freshly gathered in the autumn, the berries are about 1/3 inch in diameter, with the remains of a calyx beneath. The fruit is collected for use chiefly in the counties of Herts., Bucks. and Oxon, and is usually expressed in the locality where it is grown, by the collectors themselves, who sell the juice to the wholesale druggists, generally more or less diluted with water, the admixture being generally about 6 parts water to 1 of juice. From the dried berries, a series of rich but fugitive colours is obtained; the berries used to be sold under the name of 'French berries' and imported with those of Rhamnus infectorius from the Levant. If gathered before ripe, the berries furnish a yellow dye, used formerly for staining maps or paper. When ripe, if mixed with gum-arabic and limewater, they form the pigment 'Sap or bladder green,' so well known to water-colour painters. The bark also affords a yellow dye.