This is widespread across eastern and central North America, especially in remnants of native grassland on dry soils. In Ky. it is uncommon to virtually absent in regions that were largely forested before settlement. Although highly variable across its range, only tetraploids (2n = 40) have been reported (FNA 25). It occupies diverse and often disjunct habitats within Ky., including rocky glades, deeper soils, and riverbanks on different substrates. Glaucous plants are widely scattered, and may be relatively common in rocky riverbanks and other gravelly or sandy habitats. S. scoparium is usually the last species among dominant native grasses to flower in Ky., typically in September. But in 2012, with unusally wet spring switching to unusually hot dry summer, some areas have been observed with flowering beginning as early as June. Seed production and germination varies greatly, with old stands on infertile soils sometimes almost barren (J. & R. Seymour, pers. comm.). It can be confused with more slender forms of some Andropogon species; see notes under A. virginicus var. decipiens. Without flowers, S. scoparius may be distingiished from A. virginicus by its ligules (FNA 25); these tend to be longer on average (ca. 0.5-2 mm versus 0.2-1 mm) but they lack cilia (versus with cilia 0.2-1.3 mm long).