According to:
https://www.quackingrassnurser...
P. selskianum is now P. kamtschaticum. What makes me confused/suspicious/unsure, though, is how they say that "the edge" (cultivar) used to be kamtschaticum. I think this is just a labeling/wording mistake though. (That's a lot of "thoughs" in one sentence).
*UPDATE: P. selskianum IS kamtschaticum. That was a labeling mistake.