"Ki-sumire (yellow-violet)" (Viola orientalis) belongs to Violaceae (the Violet family). It is a perennial herb that is distributed from Yamanashi prefecture of Honshu west to Ehime prefecture of Shikoku and Kyushu in Japan. This herb grows in mountains and grasslands, and up to a height of 5-12 cm. The leaves are 2-4 cm long, basal ones are cordate and cauline leaves are narrow cordate to truncate, and pubescent on the both sides. The bright yellow flower, 1.5-2 cm across, blooms from March to May. The lip is relatively small and the spur is short. It is also called "Ichige-ki-sumire (monanthous-yellow-violet)".