What polinates a Sapalta cherry plum?

Well I have sand cherries, Nanking cherries, romance cherries, Montmorency, NorthStar, and hopefully the Evans will snap back to life. Something in that pollen soup ought to do it?

Or any info for that matter?

It just popped up at a local nursery.

My Sapalta grafts always produce well. I have lots of prunus americana type hybrid plums nearby. i.e. Toka, Kaga, Superior, Waneta, etc… plus asian plums like shiro, early golden. I have a few tart cherries like carmine jewel and monty, but no nanking or sand cherries.