This annual is widely scattered across North America, with concentrations in northeastern and Pacific states (K). However, it does not seem to be increasing measurably in Ky. or elsewhere in the southeast (W). Our only record is an apparent waif in MADI (EKY): J.S. Lassetter #348, 25 Aug 1979, "ravine behind parking lot on EKU Campus, weed in flower bed," Earlier records of C.W. Short (PH) and R. Peter (NY) are probably based on misidentified commutata, but they should be checked. E. peplus differs from commutata as follows (FNA 12, W): inflorescence with terminal pleiochasial branches 3-5, each usually 2-8 times dichotomously branched (versus 2-4, each 1-3+ times branched); dichasial bract bases obtuse (versus cordate); involucre cupulate to turbinate, 0.6-1 x 0.7-0.9 mm (versus campanulate, 1.7-2.5 x 1.5-2.5 mm); glands 0.2-0.3 x 0.5-0.6 mm (versus 0.6-1 x 0.8-1.5 mm); horns 0.4-0.6 mm (versus 0.5-1.1 mm); styles 0.1-0.2 mm (versus 0.9-1.3 mm); capsules 1.3-2 x 1.5-2.2 mm (versus 2.5-3.2 x 3 mm); columella 1.1-1.3 mm (versus 1.5-2 mm); seeds 1-1.6 x 0.6-1 mm (versus 1.5-2 x 1.3-1,6 mm), pitted only on one face, the inner face furrowed (versus finely pitted with numerous, evenly distributed, isodiametric pits); caruncle 0.2-0.5 x 0.2-0.7 mm (versus 0.6-1 x 0.7-0.9 mm).