There are two comma or anglewing butterflies of the Polygonia genus we see regularly here in NYC. You can tell them apart when their wings are spread, but it’s subtle.But they often perch upright. So the namesake comma mark on the hindwing is the tell-all. Of course, this is hard to see in the field!The fabled question mark. You won’t be the first grammarian to say it looks more like a semi-colon.
This example is perched distantly on some Duckweed, in case you are wondering about the curious pebbly-look of the background.