Witch hazel : Hamamelis virginiana, Amamelidacee family. Shrub or small tree originating from the forests of Canada and the northern states of the USA. It has whole leaves petiolate, oval and large, clearly asymmetrical at the base; the yellow flowers are grouped in axillary inflorescences. The drug consists of the leaves and barks, harvested before flowering.
The drug leaves has a very particular glycosylated tannin, amamelitannino, derived from the esterification by two molecules of gallic acid and a peculiar carbohydrate of the amammelide, amamelose. Instead, the barks contain gallic acid.
Given the content in Gallic tannins, the uses of the witch hazel concern the external use, as astringent and cicatrizant, but above all internal, as a vasoconstrictor.
