Two species are included in barnyard millet:Echinochloa utilis andE. frumentacea. These differ from each other in their genomic constitution and phylogeny. The former species originated fromE. crus-galli probably in eastern Asia, and is grown in Japan, Korea, and the northeastern part of China; the latter originated fromE. colona probably in tropical Asia, and is grown in Pakistan, India, and Nepal. “Japanese barnyard millet” is suggested as a suitable English common name forE. utilis; “Indian barnyard millet,” forE. frumentacea. In the past, Japanese barnyard millet was important in Japan as the staple food crop in districts where soil, weather conditions and irrigation systems were not suitable for paddy rice cultivation. When the rice crop suffered serious cool weather damage, the millet relieved people from starvation, especially in northeastern Japan. But the acreage devoted to the millet gradually decreased during and after the 1880s. Only the northern part of Iwate Prefecture is an exclusive Japanese barnyard millet cropping region at present. The breeding of cool- weather- resistant rice varieties and improvements in rice- growing techniques are mainly responsible for the decrease in acreage of the millet.