"Suzushiro-so" (Arabis flagellosa) belongs to Brassicaceae (the Mustard family). It is a perennial herb that is distributed from Kinki region of Honshu west to Shikoku, Kyushu, Okinawa in Japan, and eastern China, from Jiangsu to Jiangxi. It grows along mountain valleys and can reach 10 to 25 cm in height. The basal leaves are spatula-shaped to obovate, and the cauline leaves are obovate to oblong with coarse serrations. From April to June, white four-petaled flowers bloom on the racemes of the shoot apex. The Japanese name is because the shape of the flower resembles "Japanese radish".