Website/Catalog  (1956)  Page(s) [1].  
 
Japanese Tree Peonies
Fuso no Tsukasa (God of Japan) Very large globular double, white...$6.00

Article (magazine)  (Jan 1955)  Page(s) 57.  
 
Alphabetical Check List of Tree Peony Names In  Public Collections And/or Available in Nurseries 1954-1955
'Fo sotsuka' [Gardens] University of Washington Arboretum

Japanese, White, 'Fuso-no-tsukasa' (Jap. bef. 1931), Whitnal Park Botanical Gardens