Physcia adscendens (Fr.) H. Olivier
Hooded Rosette Lichen, Rosette Lichen
I cannot find a range map for hooded rosette lichen, but it occurs along the east and west coasts of North America.
Identification: Technically, this is a foliose lichen. It has an uneven branching pattern, and thickened branches, but they are not flat against the branches as with some lichens. The lichen is a powdery pale gray to greenish gray in color, sometimes with a yellow portion. It is very common. This is often found together with Physcia tenella. It appears on twigs and bark, as well as concrete and other walls, and occasionally on rocks.
Physcia adscendens on Stephen Sharnoff Photography
Physcia adscendens on the Stridvall Family Domain
Physcia adscendens on Wikimedia Commons
Physcia adscendens on www.irishlichens.ie
Physcia adscendens on Lichenology.info: Lichens of Belgium, Luxembourg and northern France
Physcia adscendens description by Thomas H. Kent, last updated 16 Aug 2013.