Very similar to Solanum nigrum but their ranges not known to overlap. The berries with four to fifteen small stone-like granules. In the Great Plains there is another species (Solanum interius) which is so similar that many authors consider it to be a subspecies. Flora of the Great Plains distinguishes this species as having a finely hairy stem, 2-4 stone-like granules per berry, and seeds 1.5 to 1.9 mm long.