The merger of Xanthoria elegans into Rusavskia, as R. elegans, advocated by Kondratyuk & Kärnefelt (2003) and accepted and followed by Arup et al. (2013) seems to be more or less widely followed (see below).
Rather than having two names on iNaturalist I have elected to merge Xanthoria elegans into Rusavskia as R. elegans because this seems to be the preferred option.
See also:
Arup, U.; Søchting, U.; Frödén, P. 2013: A new taxonomy of the family Teloschistaceae. Nordic Journal of Botany 31: 16-83.
Kondratyuk, S. and Kärnefelt, I. 2003. Revision of three natural groups of xanthorioid lichens (Teloschistaceae, Ascomycota). Ukrayins’kyi Bot. Zhurn. 60: 427–437.
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
The merger of Xanthoria elegans into Rusavskia, as R. elegans, advocated by Kondratyuk & Kärnefelt (2003) and accepted and followed by Arup et al. (2013) seems to be more or less widely followed (see below).
• Esslinger's Lichen Checklist: https://www.ndsu.edu/pubweb/~esslinge/chcklst/chcklst7.htm
• Species Fungorum: http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=410026
• Index Fungorum: http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=410026
Rather than having two names on iNaturalist I have elected to merge Xanthoria elegans into Rusavskia as R. elegans because this seems to be the preferred option.
See also:
Arup, U.; Søchting, U.; Frödén, P. 2013: A new taxonomy of the family Teloschistaceae. Nordic Journal of Botany 31: 16-83.
Kondratyuk, S. and Kärnefelt, I. 2003. Revision of three natural groups of xanthorioid lichens (Teloschistaceae, Ascomycota). Ukrayins’kyi Bot. Zhurn. 60: 427–437.