Peltigera aphthosa (L.) Willd.


Known in English as Common Freckle Pelt Lichen or Green Dog Lichen and Peltigère Aphteuse in French, Swales encountered this lichen while traveling in the Northwest Territories in June 1965.

As the common name suggests, this lichen is known for having a distinct bright green colour. Although the lichen Swales brought back to Montreal with her has lost this green colouring, the distinctive freckles can still be admired up close. 

Green Dog Lichen are known to favour alpine areas and are often found growing on rocky surfaces. This particular lichen is known to be particularly sensitive to air pollution and has been used to indicate poor air quality.