Article (magazine)  (Jan 1955)  Page(s) 59.  
 
Alphabetical Check List of Tree Peony Names In  Public Collections And/or Available in Nurseries 1954-1955
Japanese, White, 'Nagoya Castle' (Jap. bef. 1936), [Gardens] Scott Foundation, [Nurseries] William Gratwick

Magazine  (7 Aug 1929)  Page(s) 131.  
 
Tree Paeonies in Japan.
Mr. Sinzaemon Tanaka's work on the hybridization of Tree-Paeonies is much admired, and his name will be long remembered as that pf a great raiser of Tree-Paeonies. Mr. Tanaka commenced raising varieties in 1894, after he learned the method from the Rono Zasshi (then a leading agricultural journal in Japan). Since then, after many difficulties and failures, he has raised nearly two-hundred-and-fifty varieties. The following are a few of the best he has raised: Hakuo, Haku-Unryo, Nagoya-Jo, Hoo-Jo, Kanyo-Kiu, Kinpai and Godaishu.