Article (magazine)  (Jan 1955)  Page(s) 56.  
 
Alphabetical Check List of Tree Peony Names In  Public Collections And/or Available in Nurseries 1954-1955
Japanese, White, 'Beatrix', (Jap. bef. 1905), [Gardens] John J. Tyler Arboretum, Scott Foundation

Book  (1928)  Page(s) 249.  
 
Tree Peony Check List
* Beatrix. Single. (Japan.) A. Dessert 1905.

* Presumed to be in commerce, 1927.