I encountered an unusual paragraph from T.F. Stuessy (Rhodora 74(797): 1-70):

The first description of Melampodium appeared in Linnaeus’ Hortus Cliffortianus (1738) which was the reference cited in the Species Plantarum of 1753. Linnaeus in his Critica Botánica of 1737 (p. 76) clearly indicated that the name he gave to the genus was derived from “Melampus medicus graecus.” Apparently overlooking this explanation, many later workers (e.g., Gray, 1884; Cockerell, 1905) erroneously have believed the name to come from the Greek words meaning “black-foot.”

Melampodium is usually called “blackfoot daisy” in English, and of course most people familiar with the genus who know at least a few of the common roots used in Greek and Latin plant names believe that Melampodium means “black foot”. At first glance, then, Stuessy is overturning common knowledge. However, Stuessy has presented us with a false dichotomy, that Melampodium is either named for Melampus or means “black foot”. Melampodium is named for a mythological Greek healer, Melampus, whose name comes from the Greek words meaning “black foot”.