桜草 ・ サクラソウ ・ sakurasou
Japanese primrose. Primrose, A small weed with flowers that resemble sakura in shape. The flower has five petals that are slightly connected to each other at the center with a small split in each petal. Colors range from purple to, peach and white. The flowers grow on a long stem with the leaves near the surface. The Japanese name roughly translates as cherry-blossom (sakura) weed (sou).
The flower was popular in the Edo-period, and cultivated into a large number of colors. The flowers bloom in spring.