Birching is corporal punishment with a birch rod, typically given on the delinquent's buttocks or back. It was the most common school, home and judicial punishment in Europe up to the 19th century when caning gained increasing popularity.
A birch rod is a bundle of leafless birch twigs bound together, much like a bunch of flowers, to form an implement for whipping.
Today birching is no longer used for judicial punishment, and has also almost completely died out as a corporal punishment for children. In Britain birching as a judicial punishment for young offenders was abolished in 1947, but the Isle of Man (a small island between Britain and Ireland with its own legal system) caused a good deal of controversy by continuing to birch young offenders into the 1970s.
It remains as a nostalgic sadomasochistic practice, mainly in Northern and Eastern Europe.
In Finland and Russia there is also a tradition to strike one's body with soaked birch twigs in the sauna to increase blood circulation. These birch rods, however, don't have their leaves removed and thus there is no pain involved.
See also