Willis Jepson mistakenly suggested that the origin of the genus name was rather obscure, perhaps deriving from the Greek for "half-moon spear" for the appearance of the dehisced fruit on its pedicel.

In reality, the name was specifically derived from the Greek μενος (menos), meaning "force," and δωρον (doron), meaning "gift," referring to the sustenance the plants provided to the horses of Humboldt and Bonpland (1809) when they first encountered the genus in the present state of Hidalgo in Mexico.

Menodora longiflora has occasionally been treated as the monotypic genus Menodoropsis (Small, 1903) due to the extraordinary length of its corolla tube (to nearly 6 cm, as opposed to typical lengths of 0.3 to 0.7 cm in most other species), but based on both morphological and molecular data it plainly belongs within Menodora.

This is a common pattern found in many genera, but not many others with a similar amphitropical distribution also have connections across the Atlantic with Africa.

This intercontinental distribution of Menodora was often cited as evidence of continental drift or the breakup of the Pangaea or Gondwanan supercontinents, but more recently it has been judged to be the result of long distance dispersal.