The joy of many microbiome databases (greengenes in particular) is that there often isn’t a specific species name. This is one example. My suggestion here is that you use the OTU/ASV identifier and describe that. It gets away from the problem of uncultured (and therefore unnamed) species; the fact that species are a messy concept in microbiology; and makes your results more externally valid if you’re using ASVs.
Yes, those are your ASV IDs. They tell you what’s happeninhg at the species level. You can describe them as something like "An ASV belonging to genus Fusobacterium and not have to worry about species names.
I usually provide my sequences as supplementary information in my manuscript (if you have more than 1 sample, its deidentified aggregate data which is no different from providing quartiles for sample characteristics).