Creation of provisional species names for the jelly fungus genus Phaeotremella

This post is a part of a series outlining the rationale for the creation of provisional species names. For more information on provisional species names, see Stephen Russell's post here. To see other posts like this, check out the "Provisional Species Names" category in the sidebar. ​

Phaeotremella dejopia holotype

Phaeotremella is a genus of large, foliar jelly fungi and single-celled yeast forms. In 2023, I described a new species, Phaeotremella dejopia, perhaps the largest of the mushroom-forming Phaeotremella species and one with pale, wavy fronds. A reinvestigation of ITS sequence data suggests there are two more undescribed species from North America, which I give provisional species names here. 

Phylogenetic tree of Phaeotremella ITS sequences from iNaturalist and GenBank. The sequences were aligned with MAFFT, trimmed with trimAl, analysed with IQ-TREE 3, midpoint rooted and printed with ggtree in R, and edited with Adobe Illustrator. Ultrafast bootstrap support values greater than 95% are shown.

Phaeotremella sp. 'MI01'

This species is sister to the rest of the Phaeotremella foliacea species complex. More collections are required to formally describe it. The reddish coloration is notable. 

Phaeotremella sp. 'MI01' found by Huafang Su (iNat107151176)

Top section of the full Phaeotremella tree.

Phaoetremella sp. 'frondosa-WA01'

This species is sister to Phaeotremella frondosa. Collections from Montenegro and Sweden seem to be conspecific, but the ITS sequences are short. 

Phaeotremella sp. 'frondosa-WA01' found by Yi-Min Wang (iNat172923698)

Bottom section of the full Phaeotremella tree.

Other systematics issues

I believe all the sequenced specimens in the middle portion of the tree may belong to yeast forms. There are a lot of unknown lineages showing up from Russia and China. 

Middle section of the full Phaeotremella tree.