SALIX.—WILLOW. History and Description

The white or European willow is a large tree of rapid growth, native of Europe, and introduced into this country. Its flowers appear from March to June. The bark, which is the medicinal part, is readily removed from the stem during the months of July, August, and September. The dried bark is met with more or less quilled, pliable and tough, with a faint odor, and a bitter taste, combined with some astringency. Water takes up its medicinal properties, the decoction having a dark-reddish color, and which is precipitated abundantly by gelatin, carbonates of potassium, and ammonium. Lime-water gives at first a blue, and then a buff-colored precipitate. Ferric chloride throws down a dark-green tannate of iron. If the decoction contains much salicin, concentrated sulphuric acid reddens it. This species belongs to the group of willows known as the crack willows. A species much resembling it is the Salix fragilis, Linné. There are numerous species of Salix, many of which, undoubtedly, possess analogous medicinal virtues. The best rule to follow is to select those whose barks possess great bitterness, combined with astringency. Among those which have been used are the S. alba, S. caprea, S. russelliana, S. purpurea, S. nigra, and S. pentandra. The Weeping willow, or Babylonian willow (Salix babylonica) is cultivated as an ornamental tree.