Hosta Koriyama is a small to medium sized hosta from Japan. It is not registered. It has ovate, wavy, medium green leaves with a yellow edge. Scapes are 14″ tall and the flowers have purple stripes. The plant is stoloniferous. I am not aware of hybrids although the plant is known to be fertile. Usually available here potted but can be field dug. Picture is of a clump growing in our display garden.