observed on a variety of rotting wood substrate in woodland in northern snowdonia
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
I think the common name 'cup lichen' or 'pixie cup' only really applies to Cladonia species that form obvious cups, eg fimbriata, chlorophaea, diversa etc. Many others (Cladonia species and lichens in general) don't have common names.
The red bits on PC070644 and brown bits on PC070685 are pycnidia, from which apothecia (fruiting bodies) can develop.
You seem to have a mixture of species here, and I'll leave identification to an expert, but I think PC070644 shows C. polydactyla, which is very variable, but has red pycnidia (coniocraea has brown pycnidia and apothecia when they appear at all). I think at least one podetium in PC070635 is also C. polydactyla.
You have Stereocaulon vesuvianum in the background on PC070685.
Are the podetia with brown pycnidia/apothecia in the first photo also C. polydactyla? If so, is it exposure (oxidation?) that has turned them brown?
I interpret the pycnidia as being red but browned from exposure - it is often difficult to tell. But the form of the podetia and especially those basal squamules just shout "polydactyla".
Lat/Lng: 53.13702, -3.85954
OS grid ref: SH756616