Curtis has reported it for central Idaho; it’s a stretch but not out of the question to find it in Spokane. But yours is definitely what I would call black underneath. I hate measurements of lobe width, except as a relative thing: on average X. wyomingica is narrower than X. chlorochroa. I’m good with that. But a huge population like this? Not at all surprised to find wide lobes.

My take on this — and this is why I brought up Leavitt et al’s paper to start with — is that it’s not worth struggling over too much at this point! In a few years it’s all going to be stood on its head anyway. Let’s just call it X. wyomingica and move on to something we actually have a chance of understanding!

re: Lichenostigma cosmopolites

You’d know if that’s what it was. It always looks like a random network of superfine webby lines. They are 1- to few-cell-thick strands of hyphae joining conidiomata. Look for the tiny black dots the hyphae connect. Squash one under 400x to 1000x to see the conidia. Pretty tricky, though, since they are so tiny.

If you’re seeing whole areas turning black, or cracks through the cortex, then I agree, you’ve “just” got necrosis. Interesting in itself, no doubt, but not so easily pigeon-holed as a handily named parasite.

Thanks Jason for your feedback :)

re: X. chlorochroa: I totally agree about the possibility that it is X. chlorochroa, the primary distinguishing morphological features listed in Lichens of North America (Brodo), Macrolichens of the Rocky Mountains (McCune and Goward) and Macrolichens of the Pacific NW (McCune and Geiser) and “Key to Xanthoparmelia in North America, Extracted from World Keys of Hale 1990” (Thomson 1993) include 1) lobe width (X. chlorochroa lobe width is generally > 1.5mm; X. wyomingica lobe width is generally < 2mm wide), and 2) the degree the the margin incurls. Brodo additionally places attachement to substrate as a defining characteristic, while McCune and Goward and McCune and Geiser do not

re: Molecular Phylogentics and Evolution: abstract seems to also indicate that the current species groupings for Xanthoparmelia are incorrect, the morphological distinctions that have delineated the current species don’t neatly overlap with the genetic clusters at species level (if I am interpreting the abstract correctly). Maybe you’re right, Jason, that this is an example of where habit traits are more variable, not a distinguisher of species.

Maybe its Xanthoparmelia chlorochroa, and if that turns out to be right I get to add a new species to the list for Turnbull! :) Currently there’s only X. mexicana, X. digitiformis and X. wyomingica on their list.

re: Black fungus, it definately could be filaments, that would make sense, unless its conidioforms of some sort? That could be possible, yes? The black cuts extend into and through the upper cortex, does the L. cosmopolites do the same? I’m still looking for areas that have the neat mycelial forking pattern of the Lichenostigma cosmopolites. The pattern I’m finding looks more like splotchy necrosis of the upper and lower cortex along with a few long black thick cuts that do not fork, maybe a similar species as L. cosmopolites or the same species, just at a different stage of development or in different environmental conditions? Super neat that Xanthoparmelias have a specific parasite! Thanks Jason!

Are you sure these are actually cuts, and not minute filaments on top of the thallus? There is a very common and ubiquitous parasite Lichenostigma cosmopolites that likes Xanthoparmelia thalli.

But note that there are several others that are virtually identical but less attached to the soil, esp. X. chlorochroa. I’ve seen research suggesting that all of the species of Xanthoparmelia with broad lobes and salazinic acid may need serious revision; the habit (vagrant through fully attached) may not be a good character. [Leavitt, S. D., L. A. Johnson, T. Goward & L. L. St. Clair 2011: Species delimitation in taxonomically difficult lichen-forming fungi: An example from morphologically and chemically diverse Xanthoparmelia (Parmeliaceae) in North America. – Molecular Phylogenetics and Evolution 60(3): 317-332.]

(Welcome to MO, by the way, Nastassja!)