Stereocaulon from roofing felt

Hello everyone,

This Stereocaulon was found in northern jutland, Denmark and as the title says it was growing on roofing felt. It was sent to me by a user of one of the national citizen-science portals (http://www.fugleognatur.dk), and I am having some issues identifying it.

There were samples from 4 thalli in the parcel, all from the same location and substrate. One of these was a characteristic S. dactylophyllum, but the remaining deviate from this quite a bit both in the shape of phyllocladia and in the thickness of tomentum. It is also P+ orange, however. Going through Lamb’s key for the arctic and boreal species I tentatively arrive at S. dactylophyllum var. occidentale, but the phyllocladia are very variable within the same thallus and I can’t find any photographs of this taxon online to compare, so I am very uncertain.

Any thoughts or comments on the ID or how to proceed are more than welcome.

-Jonas

[attachment=1]Stereocaulon cf. dactylophyllum (tagpap, Gerth) 1-1s.jpg[/attachment]
Overview of the thallus; pseudopodetia < 2 cm and they are distinctly dorsiventral

[attachment=2]Stereocaulon cf. dactylophyllum (tagpap, Gerth) 1-2.jpg[/attachment]

[attachment=3]Stereocaulon cf. dactylophyllum (tagpap, Gerth) 1-3.jpg[/attachment]

[attachment=4]Stereocaulon cf. dactylophyllum (tagpap, Gerth) 1-4.jpg[/attachment]

[attachment=5]Stereocaulon cf. dactylophyllum (tagpap, Gerth) 1-5.jpg[/attachment]
Close-ups of phyllocladia – I have tried to capture some of the variation within a single thallus

[attachment=0]Stereocaulon cf. dactylophyllum (tagpap, Gerth) 1-6.jpg[/attachment]
Lower surface