This small weedy native annual is widely scattered across eastern North America; the closely related S. occidentalis S. Watson occurs in Pacific states (W). S. decumbens often grows in gravel roads an sidewalks, beneath the feet of botanists, but it tends to be overlooked in general floristic surveys. The original habitats of decumbens before settlement are generally unknown, but may have included open eroding animal trails and perhaps burned areas. (It is not typical of xeric rocky glades or hydric shorelines.)