This is a non-registered seedling of
Japan. It is a medium size
hosta with green foliage and pure white flowers in
The Hostapedia by Mark Zilis (2009), "...sometimes listed as
H. tsushimensis 'Shirobana'...H.
tsushimensis albiflora and H. tsushimensis albo-flora."
Mikiko Lockwood in an article on The Hosta Library titled,
A Little About Japanese Hosta Terms defines the term shirobana as white flower.