It would be helpful if iNaturalist would offer the option to identify the Sphagnum subgenera when the exact species cannot be determined.
Hi Cathy, welcome to the forum! The best way to raise issues about specific taxa is to go to the taxon page, click Curation, then Flag for Curation, then leave a short note about what needs to be done. That will bring it to the attention of volunteer curators who can add additional taxonomic nodes.
I started a flag, so let’s continue the conversation there: