Website/Catalog  (1956)  Page(s) [1].  
 
Japanese Tree Peonies
Horaisan (Mountain of Heavenly beauty) Large, rose-red semi-double...$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
Japanese, Lilac Rose, 'Horaisan' (Mt. Horai) (Mountain of Heavenly Beauty) (Jap. bef. 1926), [Gardens] University of Washington Arboretum, Whitnal Park Botanical Gardens