Dear Jim, Jim, and All,
Paeonia japonica as I have it ± corresponds to the Russian P vernalis,
and it's rose pink rather than white. That said, a distinction of
horticultural significance is that P japonica flowers about three weeks
earlier than obovata. (Again, obovata as I have it.)
Jim W: wish you every success with your work in the works. Look
forward to having my very own copy of it real soon.
All the best,
Don