Panicum miliaceum is a grain crop with many common names, including proso millet, broomcorn millet, common millet, hog millet, Kashfi millet, red millet, and white millet. Archaeobotanical evidence suggests millet was first domesticated about 10,000 BP in Northern China. The crop is extensively cultivated in China, India, Nepal, Russia, Ukraine, Belarus, the Middle East, Turkey, Romania, and the United States, where about half a million acres are grown each year. The crop is notable both for its extremely short lifecycle, with some varieties producing grain only 60 days after planting, and its low water requirements, producing grain more efficiently per unit of moisture than any other grain species tested. The name "proso millet" comes from the pan-Slavic general and generic name for millet (, , , ). Proso millet is a relative of foxtail millet, pearl millet, maize, and sorghum within the grass subfamily Panicoideae. While all of these crops use C4 photosynthesis, the others all employ the NADP-ME as their primary carbon shuttle pathway, while the primary C4 carbon shuttle in proso millet is the NAD-ME pathway. Evolutionary history Panicum miliaceum is a tetraploid species with a base chromosome number of 18, twice the base chromosome number of diploid species within the genus Panicum. The species appears to be an allotetraploid resulting from a wide hybrid between two different diploid ancestors. One of the two subgenomes within proso millet appears to have come from either Panicum capillare or a close relative of that species. The second subgenome does not show close homology to any known diploid Panicum species, but some unknown diploid ancestor apparently also contributed a copy of its genome to a separate allotetraploid species Panicum repens (torpedo grass). The two subgenomes within proso millet are estimated to have diverged 5.6 million years ago. However, the species has experienced only limited amounts of fractionation and copies of most genes are still retained on both subgenomes. A sequenced version of the proso millet genome, estimated to be around 920 megabase pairs in size, was published in 2019. Domestication and history of cultivation Weedy forms of proso millet are found throughout central Asia, covering a widespread area from the Caspian Sea east to Xinjiang and Mongolia. These may represent the wild progenitor of proso millet or feral escapes from domesticated production. Indeed, in the United States, weedy proso millet, representing feral escapes from cultivation, are now common, suggesting current proso