Hello!
My wife had a couple dozen peony cultivars in her gardens and kept meticulous records. This one is allegedly "Mrs. A. M. Brand". The description for stems and foliage match, and the specimen is 32" tall. Alas, the flowers have these little red flecks in the center which are typical in "Festiva Maxima", which I also have. It stands well over four feet tall. The blooms are bigger and the foliage isn't as dark or dense. There are very few "Mrs. A. M. Brand" photos to compare to, so I don't know if this may be a color variant or not. The flower sure looks like "Festiva Maxima" though.
TIA for your input.
Mark