According to P. Adanick (pers. comm.), some A. blitum in Ky. appears to be ssp. emarginatus, which has been distinguished from ssp. pseudogracilis as follows (W): plants prostrate (versus ascending); leaves 0.75-3.5 cm long (versus 1.5-6 cm); inflorescences mostly axillary cymes, the terminal reduced or absent (versus primarily terminal, thin and flexuous). Ssp. emarginatus is typical of drier sites (such as gravel parking lots) and perhaps less closely associated with greenhouses. In Ky. it appears largely restricted to the Bluegrass region. However, identifications have been uncertain in some cases.