The Chugai Nursery, Yamamoto, Japan, Catalog 1940-1941: Tree peony, New & Rare Varieties:

Wister (1961):

'Tsukumo-jishi' (Great Multitude of Lions)

(Japanese tree peony - Reddish-Purple Flowering group) In the large photograph this flower is asymmetrical bilaterally. This is called perfect "Shishizaki". It rarely happens. Medium size. Midseason

Carsten Burkhardt's Web Project Paeonia - The Peony Database

TTTT06

TTTT07

TTTT08