Mapledust lichen is common in eastern North America.
Identification: This lichen is pale yellow to greenish. It is thin and powdery looking, and may appear as a continuous coating, or be divided into patches. It is often scaly (leprose). A white fibrous band, the prothallus, borders the lichen. On close inspection, there may be one or two bluish zones of hyphae, the actively growing regions.
Lecanora thysanophora at the Consortium of North American Lichen Herbaria
Lecanora thysanophora on Stephen Sharnoff Photography
Lecanora thysanophora on www.jstor.org
Lecanora thysanophora on the Mushroom Observer
Lecanora thysanophora description by Thomas H. Kent, last updated 16 Aug 2013.