 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 Δορον ("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.