Ledum latifolium, Ledum palustre.
Ledum latifolium Jacq. Ericaceae. Labrador Tea.
Northern climates. The leaves are said to have been used as a substitute for tea during the Revolutionary War. Lindley says the leaves are used to render beer heady.
Ledum palustre Linn. Marsh Rosemary.
Northern and arctic regions. This plant furnished a tea to Richardson in his arctic journey. (Marsh Rosemary has a weird sweet scent and gives people headaches. It's not suitable for "a tea" really. -Henriette)