A pale orange lichenicolous fungus, forming small patches parasitising Physcia lichens and other corticolous lichens.  The lichen thallus becomes bleached.  The patches are made of minute rounded bulbils, which are the asexual stage that produce conidia. 

Colour is subjective, especialy in a photograph or in artificial light. Microscopic examination of the contents of the orange material is recommended.  A water drop test has been used to separate this species from Illosporiopsis christianseii; see paper by Ann Claypole for British Lichen Society; link below. 

Illosporiopsis christiansenii and Marchandiomyces corallinus are pink lichenocolous species also affecting Physcia and other lichens.

Good images required, showing host species of lichen as well as fungus.  We recommend microscopic examination.

Deciduous twigs and branches.   A parasite of corticolous Physcia spp., occasionally also attacking neighbouring thalli of other lichens.

All year.

Quite widespread in Britain but not particularly well recorded.

Status in Leicestershire and Rutland not known.

https://britishlichensociety.org.uk/sites/default/files/Erythricium%20aurantiacum.pdf

https://britishlichensociety.org.uk/sites/default/files/2023-11/Illosporiopsis%20christiansenii%20-%20Ann%20Claypole.pdf