Panicum dichotomiflorum aka Smooth Witchgrass

Panicum dichotomiflorum, also known as fall panicgrass, autumn millet, or fall panicum, is a species of Poaceae "true grass" that is native to much of the eastern United States and parts of Canada. It can also be found in the Western United States through California, possibly as an introduced species. This annual grass can grow decumbent or erect up to a maximum height of one meter or three feet and has hairless leaves that distinguish it from Panicum capillare or Witchgrass. Fall Panicgrass is a versatile plant that grows in many types of habitat, including disturbed areas and chaparral habitats. It bears a large open panicle inflorescence of up to 20 centimeters long and fanning out to a width of 16 centimeters. As a houseplant, Fall Panicgrass is a super rare plant that requires regular watering to thrive and does best in long-lasting, direct light while being less than one foot from a window. It prefers well-draining soil and should not need added fertilizers if you repot it each time it doubles in size. On the other hand, if you want to get rid of this plant, manual weeding is recommended.