Creeping Bellflower has very showy flowers. Among the Eurasian bellflowers that are cultivated, this is the species that most often escapes in part because it is more commonly cultivated. A species that has naturalized less often in Illinois, Campanula glomerata (Clustered Bellflower), has more erect flowers that are clustered together at the apex each central stem. The flowers of this species have sepals that are longer and wider than those of Creeping Bellflower. The circumboreal Campanula rotundifolia (Harebells) and native Campanulastrum americanum (American Bellflower) are quite distinct from Creeping Bellflower. Harebells has linear leaves along its stems and its bell-shaped flowers are smaller in size (usually less than 1" in length) than those of creeping Bellflower. The flowers of American Bellflower have shallow corollas that are star-shaped with widely spreading lobes; the older scientific name of this latter species is Campanula americana.