Erythricium aurantiacum on Physcia tenella

This is potentially the basidioma of Erythricium aurantiacum, which is described as “floccose” (i.e covered in woolly tufts). There is a picture in Lichenicolous Basidiomycetes by Paul Diederich https://www.mnhn.lu/science/flora-of-lichenicolous-fungi/?lang=en” class=”bbcode_url”>https://www.mnhn.lu/science/flora-of-lichenicolous-fungi/?lang=en on page 74, but this shows it as a small patch associated with the typical bulbils, which are curiously absent from your picture. If it is then it should have basidia with four basidiospores (see drawing in Lichenicolous Basidiomycetes)

I have just collected something a bit similar on Physcia adscendens/tenella, but this is certainly not Erythricium aurantiacum.

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The Physcia thallus with the pale orange infection

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Close view, the fuss of basidia? visible on the edge of the thallus

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Microscope view of basidia? supporting a single spherical basidiospore? 10 – 13µm diameter. Or possibly these are the conidia of an asco.

I have no idea what this is.

Neil

Fay

Could your sample be a hyphomycete, Neil?

For all I know yes, being an ecologist and not a mycologist this is a bit beyond me!

Neil

Actually thanks to Vince Giavarini, I have a tentative identification on my odd material. He has seen Nectriopsis physciicola associated with this type of material, suggesting that this may be the anamorph (asexual sporing form producing conidia) of this fungus. Searching on the internet there is also a report for very similar material associated with another Nectriopsis species in South America, which was thought to be the anamorph of that species, but this was not confirmed with sequencing. (See figure 16 https://pfsyst.botany.pl/pdf-120091-48872?filename=Biodiversity%20assessment.pdf” class=”bbcode_url”>https://pfsyst.botany.pl/pdf-120091-48872?filename=Biodiversity%20assessment.pdf. So Fay was right this does appear to be a hyphomycete.

Neil