This stoloniferous perennial is most common in more northern and western regions of North America, where it can be a persistent weed. Variation needs further study across its range; 2n = 36 and 54 (FNA 19, Y). For Ky. the only records are colls. from JEFF (MM) and ROWA (MDKY). Both var. arvensis and var. glabrescens (Gunth.) Grab. & Wimmer (= ssp. uliginosus (M. Biebertein) Nyman appear to be represented from ROWA.