If you look closely at some of the lobes, esp. on the right side, you can see soralia in the center of the lobe. R. farinacea has exclusively marginal soralia. Nice photo, since it shows this detail!
Ken-ichi Ueda
2013-01-27
2013-01-27 13:31:41
United States of America, California, Knowland Park, Oakland, California, US
37.753927 -122.139631 EPSG:4326
<a href='https://www.inaturalist.org/observations/189730' target='_blank' style='color: blue;'> Original observation #189730 (iNaturalist)</a>
Hm, not entirely sure. Sorredia dont seem entirely discrete, but even so I think it might be <i>R. farinacea</i>.