But he didn’t say anything about black apothecia scattered around them. And there is also some “dirt” on top of them – too tiny for me to see under my microscope. I better send this to Jason…

Not all lichenologists are into parasites. The folks at NYBG are. Kerry Knudsen is. Probably more. But they still aren’t “mainstream”.

I do have several observations with parasites on them – by looking at anything unusual in patterns and colors.

growing on Candelariella. (observation 210142) The best way to find neat parasites is to look for really “dirty” specimens in old populations. Look for (with hand lens!) tiny black “pycnidia” (usually actually perithecia of parasites) immersed in the apothecia of Lecanora s. lato, or in the thallus of various crustose and macro species. It’s rarer (but commensurately more exciting!) to find hosts actually deformed by the parasites. Look for “galls” or warts, either discolored or full of black dots. And of course, if you ever see something like a Physcia or Phaeophyscia with what look for all the world like lecideine apothecia, that’s tremendously exciting. :) Could be Abrothallus or one of several other apothecioid unlichenized parasitic fungi, all pretty rare. If there’s a particular host that’s really abundant in an area, that’s also a good place to start. Again, look for anything obviously unusual, but also take a hand lens to sheltered or dusty or discolored or dirty populations, and see if some of that discoloration may be due to parasites. Invariably, if a species is really abundant (e.g., Sporastatia testudinea in the alpine, Caloplaca trachyphylla in Canyonlands, Letharia in the High Sierras), then it will frequently be found with parasites. In my experience. Good luck! :)

to find parasites, whether lichens or fungi or something else. Also everything unusual and fun – unlike common stuff everyone is accustomed to. I look for parasitized lichen, lichen afflicted by unknown forces, the ones growing on unusual substrate and the ones just not looking like the rest of their peers in the same species, for whatever reason.
There is definitely other species of lichen fighting for living space with Candelariella in this case, but it looks more like Candelariella is overcoming those other species and is perching on top of others’ thallii.

I’m obsessing over parasitic lichens these days, always looking for Carbonea and other fun things. But I’m invariably wrong: the ones that look parasitized are not, the ones that are I’ve just collected accidentally! Fiendishly devious things, those parasites… ;)

Under microscope I see at least two or three species with dark apothecia, some without thallii. None of them seems to sit directly on top of Candelariella, but right next to it. There is some dark tissue in between the cracks too, but I can’t see better.

This is a supremely unphotogenic species everywhere else in the world! ;)

But wait… wait… do I see little black dots mixed in with some of those thalli? Could there be some Carbonea vitellinaria or Polysporina lapponica sharing those galaxies?…

like stars (or rather remote galaxies) shining against the “dark sky” of a sombre flat sandstone surface.