This largely midwestern annual was mapped in Ky. by Hitchcock (1950), but verified colls. have not been located. A. curtissii (Gray ex S. Wats. & Coult.) Nash was also mapped in Ky. by Hitchcock and others (M), and may include a coll. from MCRA (see under dichotoma). A. curtissii has been treated as a variety of basiramea (Cr) or dichotoma (FNA 25). Its morphology and distribution appear somewhat intermediate between those two species. W considered it a distinct species, but largely adventive in southeastern states.