Since 1934, the rotundifolia complex of Amblycorypha has consisted of two named species: Amblycorypha parvipennis Stal, occurring from the Mississippi River westward into the eastern edges of the Great Plains, and Amblycorypha rotundifolia, occurring in most of the eastern United States. The latter entity is here shown to consist of at least three species with distinctive calling songs and different but overlapping geographical distributions. At 25°C, A. rotundifolia (Scudder) produces ≈26 calling song units (phonatomes) per s, whereas Amblycorypha bartrami n. sp. Walker, A. parvipennis, and Amblycorypha alexanderi n. sp. Walker produce ≈10, 5, and 2.8 ph/s respectively. Amblycorypha rotundifolia occurs from Illinois to New York and southward along the Appalachians to northern Georgia. Amblycorypha bartrami occurs in the southeastern states, and A. alexanderi broadly overlaps the distributions of the other two eastern species. Where A. alexanderi and A. rotundifolia are sympatric, the two occur in similar habitats; where A. alexanderi and A. bartrami are sympatric, A. bartrami occurs in more xeric habitats. No morphological characters were found that reliably identify the three eastern species, yet no fewer than three species must be recognized to provide names for populations that behave as distinct species where they co-occur.