Rudbeckia hirta var. pulcherima (aka R. serotina); Asteraceae (aster family)
Deisgnated the “floral emblem” of the state of Maryland in 1918 by the General Assembly, this short but showy plant grows almost everywhere in the US and Canada (but not in Arizona or Nevada). It likes sunny habitats, and is one of twenty two species of Rudbeckia native to the US.
Strangely enough, I almost never find them in my target area. I found this one in early October, the first one I’d seen in the wild this year.
Though they look like sunflowers (and are related), the Rudbeckias tend to have reflexed ray flowers and cone-shaped disks. See also tall coneflower (fotd Aug. 21) and purple-headed sneezeweed (fotd Aug. 25).