The Chugai Nursery, Yamamoto, Japan, Catalog 1940-1941: Tree peony, Tree peony, Winter-Flowering Peonies, (Everblooming Peonies) Winter flowering peonies have their beautiful flowers from the beginning of November till January and again they flower in spring together with ordinary spring flowering peonies, hence the name of ever-blooming peonies. Their flowers are as large and beautiful as spring flowering varieties. There is very rare exception of not flowering in winter. however, but in whitch case it will flower in next winter

Wister (1961):

'Sekkaku' (Snowy Crane) (Jap. bef. 1932)