Posting some photos of presumed Fuscopannaria from Fidalgo Island, WA, on serpentinite, open forest, near salt water, about 40m elevation. Thallus margins pruinosity distinctly blueish. Spores average 12x7µm, most with large oil drop.
Feeling a bit out on a limb in thinking Fuscopannaria praetermissa group, and further out wondering about F. thiersii, of which Jørgensen (2000 Survey of the Lichen Family Pannariaceae on the American Continent, North of Mexico. The Bryologist 103, 4 pp. 670-704) mentions “may be a specialist of heavy-metal and/or ultrabasic rocks”. Not sure how to interpret McCune and Geiser 2009 regarding F. aurita - “ear-shaped frosted lobules differ from the ascending knobs sometimes found in F. praetermissa and F. thiersii” but thinking mine is more knobby. Not many photos available to compare.
Looks like F. praetermissa group to me, but hard to say which one from the scale of the photos (need to zoom in quite a bit to tell). In F. aurita many of the propagules are flattened (i.e. lobule like). It is possibly the commonest species in this group at low elevations in Oregon and Washington.
But even close up these can be challenging and there seem to be intermediate forms.
For interest sake posting some quite close images - view full size (1080 vertical)
I'm leaning toward F. aurita, but this thallus is so compact and tight. Not certain.