Bird's foot trefoil (Lotus corniculatus var. japonicus) belongs to the Fabaceae (the Pea family). It is a perennial herb that is distributed widely to Japan, as well as the Korean Peninsula and China. This herb grows in sunny roadsides or grasslands, and the stems crawl on the grounds. The peduncles are borne at the axils, and the 1-3, yellow, papilionacenous flowers bloom from April to October. It resembles to Bird's foot trefoil (Lotus corniculatus var. corniculatus) that is defined by the hairy stems and leaves, and the arrangement of annular 3-7 flowers around the peduncle.