Danny Van Eechaute of Belgium
registered this sport of H. 'Koryu' in 2004. It forms a medium
size plant about 10 inches high with dark green leaves which
have a lighter green medial (center) variegation. Pale purple
flowers bloom in September. It varies from the mother plant by
having smooth textured leaves.
Mikiko Lockwood in an article on The Hosta Library titled,
A Little About Japanese Hosta Terms defines the term midori
as green and the term koryu or Kouryu as a raised ridge along the center
of a leaf.