There are several species of toad that can be found in Iowa. The moniker "Iowa Toad" is a common name, which to be quite honest, really means nothing. Common names are different everywhere you go because we all assign different identifications. In Costa Rica half the species don't even have common names, do you just make them up and hope they stick.

Anywho, in Iowa there are 4 species of toad.
B. americanus (American Toad)
B. cognatus (Great Plains Toad)
B. woodhousei (Woodhouse's Toad)
Scaphiophus bombifrons (Plains Spadefoot Toad)

Alex