This variable allo-octoploid (2n = 88) annual is probably derived in part from lapathifolia (Kim et al. 2008). In Ky., flowers are usually pinkish but they can sometimes be whitish; plants vary from pubescent to glabrous. Possible distinction of the less pubescent northern taxon, var. laevigatum Fern. (as described within Polygonum), deserves further attention (F). However, varieties within this species are not readily recognized (FNA 5). See also notes under bicornis and careyi.