Geum rivale, Geum urbanum.
Geum rivale Linn. Rosaceae. Indian Chocolate. Purple Avens. Water Avens.
Northern temperate regions. Johnson says this plant was often used in olden times to flavor ale and other liquors.
Geum urbanum Linn. Avens. Clove-Root. Herb Bennett.
Northern temperate regions, Australia and New Zealand. The root, according to Lindley, is used as an ingredient in some ales.