jamesphelan1217's Identifications

Gold Dust Lichen (Chrysothrix sp.), photographed on an old acacia tree on the hill above the upper reaches of Newark Slough at the San Francisco Bay National Wildlife Refuge in Fremont, CA. Three species are possible (Chrysothrix candelarian, C. granulosa, and C. chlorina), but it is impossible to tell one of these lichens from the others visually. Identification to species would require either a microscope or certain chemical tests.

References:
1) Sharnoff, Steven. A Field Guide to California Lichens, Yale University Press, New Haven, CT, 2014, pp. 253-254.
2) "Chrysothrix spp.," Consortium of North American Lichen Herbaria. Retrieved from http://lichenportal.org/portal/taxa/index.php?tid=51832&clid=0&pid=1&taxauthid=1
on 8/22/18.
3) "Chrysothrix candelaris," Consortium of North American Lichen Herbaria. Retrieved from http://lichenportal.org/portal/taxa/index.php?tid=52529&taxauthid=1&clid=0 on 8/22/18.
4) "Chrysothrix chlorina," Consortium of North American Lichen Herbaria. Retrieved from http://lichenportal.org/portal/taxa/index.php?tid=52530&taxauthid=1&clid=0 on 8/22/18.
5) "Chrysothrix granulosa," Consortium of North American Lichen Herbaria. Retrieved from http://lichenportal.org/portal/taxa/index.php?tid=52531&taxauthid=1&clid=0 on 8/22/18.