Book  (Jan 2000)  Page(s) 73, 77.  
 
Page 73: [Plant and flowers are nearly indistinguishable from 'Early Windflower', which blooms a week to ten days earlier...]
Page 77: Late Windflower Herbaceous Peony. Saunders 1939. The result of a cross between Paeonia beresowskii and P. emodi...

Book  Page(s) Book 3, p. 15.  
 
Beresowskyi x Emodi
12212-33 22 Beresowskyi X Emodi
several dead. ...lifted 1938.
This strain, I now call Late Windflower. They have been much propagated and distributed. They are all very closely alike & I have made no attempt to keep the numbers separate....