Hime-Urashima-So × Urashima-So (Soshin)
Arisaema triphyllum var. pusillum
It is a hybrid of A. kiushianum and A. thunbergii subsp. urashima that provided by Mr. S. As shown in the image, there are three features.
1. Slightly larger than A. kiushianum.
2. The stripes of spathe are inconspicuous .
3. There is no white patten similar to fungi inside.
Great care should be taken against introgression of populations, such as escape.