The Thunberg's meadowsweet (Spiraea thunbergii) belongs to Rosaceae (the Rose family). It is a deciduous shrub that is distributed from Kanto district of Honshu to Shikoku, Kyushu in Japan, and China. This shrub grows on rock crevices along streams, forms a clump and can reach 1-2 m in height. Leaves are lanceolate and alternate. True white flowers on the umbels come from March to April. There are several cultivars with pale pink flower. In Chinese, it is called "珍珠綉線菊" (zhen zhu xiu xian ju).