This is a non-registered sport of
H. longissima from Japan. It is a small size
hosta with narrow, green foliage with gold medial
(center) variegation. Flowers are medium purple in color with
purple anthers and are borne from mid-September to October.
May also be sold in Japan as H. 'Kinakafu
Mikiko Lockwood in an article on The Hosta Library titled,
A Little About Japanese Hosta Terms defines the term kinakafu or ki nakifu as yellow-center(ed), the term mizu as water, 'Mizu Giboshi' or
H. longissima, the term nagaba as narrow long leaf(ed).
and the term nakafu as medio-variegated.