I got a big book on lichens. We'll see how far I get on this one. Next time I need to bring a hand lens.Ok, so despite the fact that the key seemed relatively easy to follow, it didn't lead me to anything that looked even remotely right, so I resorted to flipping, and arrived at Tuckermannopsis. That plus the range maps and some Googling lead me to Tuckermannopsis (Cetraria) orbata, the variable wrinkle-lichen. Anyone have an opinions?Observed in Huckleberry Botanic Preserve, Oakland, CA, USA. The clump shown is maybe 4-5 cm wide.