See this name description for Xanthoria.

Where does that leave observation_88828?? I’m voting for ulophyllodes…

I hope I will not be disqualified and kicked out of MO for adding few photos to the same opbservation, but taken a week later. I don’t know if that kind of cheating is tolerated :-) They’re the very same cluster of lichen, and only a week apart.
On the different note, this X.weberi is on rock and has very distinct features. But it’s not like the observation 88828 at all. So what’s that one?

Now I know what to look for in this species. The only problem is – I didn’t know that similar stuff used to be called X.fulva. I thought X.fulva was the stuff like in those observatons you mention just below – with raised central lobes and broad lobe tips. Now I don’t know what those are. They’re pretty common, though, so I’ll obtain a specimen soon, I hope.

Doesn’t this look just like the photo in Lindblom’s 2006 paper? Narrow ascending lobes, soredia under tips, colonial growth form, a bit too orange perhaps, but this is otherwise a perfect match. This is what I’m used to X. fulva looking like.

Now. You’ve also got some undeniable X. ulophyllodes (e.g., observation 88909, observation 88899). What about all the broad-lobed things in between with erect central lobes, pimply pycnidia and no rhizines?? (e.g., observation 88828, observation 88906)

I was actually taking photos of Candelaria concolor and some Caloplaca species when I got this one – I only realised this when I uploaded photos to my computer. I will definitely go back and retake the photos at some point.