Lobaria Pulmonaria or as it is more commonly called lungwort. It is a foliose lichen and its thallus is lettuce green, quite leathery with ridges and grooves on the surface. The thallus is up to 15 cm in diameter. The asexual reproductive structures can be seen on the surface. Small pockets of cyanobacteria are often seen on the lower surface of the thallus, they are darker than the green surface of the thallus. When it is wet, it becomes a bright green, but it will dry out to a dark brown color. Look for small hairs on the underside.
It looks quite like the inside of the lungs, the lichen’s common English name is derived from this association. Commonly used for asthma, urinary incontinence, and lack of appetite. It can be used as medicine to treat hemorrhages and eczema, and it is used as a remedy for coughing up blood by the Hesquiaht people of coastal BC.
Lungwort has also been used to produce an orange dye for wool, in the tanning of leather, in the manufacture of perfumes, and as an ingredient in brewing.