This is a widespread variable winter-annual (2n = 16, 30, 32) that occurs on "dry, sterile or sandy soil" in northern and western states (Cr, FNA 7). The few records from southeastern states may represent accidental introductions (W). Its status in Ky. remains uncertain. The SERNEC database indicates a coll. from CAMP at LSU that needs to be checked: J.W. Thieret 48220, 20 Apr 1974, weedy roadside at reservoir 1 mi ENE of Alexandria. There are also a few old or obscure reports: as D. hispidula Michx. by Short & Peter (1834); as D. caroliniana Walt. from WARR by Pr; and as D. reptans, without detail by BA. Colls. need to be searched for at MO and elsewhere.