Campanula pauciflora Lam. ex Steud. 1840 not Desf. 1833
Campanula planiflora Lam.
Campanula subulata P.Beauv. ex A.DC.
Phyteuma americanum Hill
Specularia americana (L.) Morgan ex J. James
Campanula americana, the American bellflower, is a tall bellflower native to eastern North America from the Great Lakes region south to Florida and from the Dakotas east to New York. This native plant is an annual or biennial from 2-6' tall. Its flowers are light blue to violet and are usually arranged in elongated clusters. It is an unusual bellflower in that its flowers are usually flat and not bell-shaped. It has a varying life-history with seeds germinating in the fall producing annual plants and spring-germinating seeds producing biennial plants. It is generally insect-pollinated, and does not usually self-pollinate.
Some authorities, including the USDA Plants database  consider the name Campanulastrum americanum to be the valid and correct name for this species.