Here's something I've google translated from a norwegian description of the plant:
"Ground Ivy is a plant with a strong connection to magic and witchcraft. The story goes that on Valborg Mass Eve, the night before 1 May was Ground Ivy picked and tied in a wreath that was worn on the head during Mass the next day. Then one could detect witches by looking at their eyes.
Ground Ivy had in ancient times importance as a spice in beer brewing. The herb gave the beer a good, tart flavor, making it brighter and more durable. We know that the Ground Ivy was used in this way in the 1500s, but the herb was later replaced by hops. Ground Ivy could also be used as vegetable, preferably in soups and stews, or as an ingredient in salads.
The chest diseases were Ground Ivy considered to have particularly good effect. In England they made a drink called Tea Gill (Gill Ale) of dried cross button that got in boiling water. The drink was sweetened with honey, sugar and liquorice. Gill Tea was a popular folk remedy cure for prolonged cough. The drink seemed cool the fever, and was used to relieve violent coughing with lung disease.
Also by a number of other ailments were Ground Ivy previously widely used. The English herbal doctor John Gerard wrote in his Herbal of 1597 that the herb was effective against tinnitus and hearing impaired, but also useful for all kinds of inflammation, the spots on the cornea, and the itching and pain in the eyes. Also against toothache would Ground Ivy be an excellent remedy. Hildegard of Bingen (1098-1179), in their writings also extensive discussion of Ground Ivy's medical effect. There is enough content of tannins and bitter principles that made herb in ancient times had as good a reputation as a drug against a variety of diseases."
