Previously posted Protblastenia incrustans from marble band at Sibley Pass, 1860m, North Cascades. Weather and time limited what I could do there last month. (Previous visit in 2010 weather was even worse.) But surprised by how much on 2 small pieces of marble from August 29. Stumped by a Staurothele (see posted photos):
endolithic; surface of marble varies but seems darker than elsewhere, seems like some association with minute pits with cyanobacterea (I think)
black perithecia, ≤o.4mm, leave pits in marble surface
involucrellum extends towards base of exciple
periphysoids present
hymenial algae almost round
asci clavate, (appearance of ocular chamber sort of, which Staurothele should lack - see one photo)
8 spores/ascus
spores become dark brown, muriform, size varies considerably - say 32-40 x 20-28 µm