Book  (1928)  Page(s) 270.  
 
Tree Peony Check List
*Yo-so-oil. (Japan, 1910.) Henry & Lee 1926; Japanese Nursery Co. 1910 as new.

The varieties marked (*) are believed to be in commerce or in existence at the present time.

Website/Catalog  (1921)  Page(s) [6].  
 
Japanese Peonies
Yosooi...$3.00

Book  (1907)  Page(s) 230.  
 
2688. YOSO OI; P. moutan.
(1) 1903, Jap. Cat. Fewkes' Cat.