"Lungwort", or "lung lichen" (Lobaria pulmonaria) on a sugar maple (Acer saccharum) in New Brunswick. This lichen is used in Britain as an indicator of undisturbed ecosystems.
Lobaria pulmonaria reminded medieval European healers of lung tissue, and they took this as a sign that it was a remedy for lung ailments. The Hesquiat people of British Columbia used it as a treatment for coughing up blood, and it was also used for lung troubles in Darjeeling and Sikkim.
Lobaria pulmonaria was used at a Siberian monastery long ago in brewing a bitter beer.