The only species is Marshallocereus aragonii that is found in Costa Rica, El Salvador, Guatemala, Honduras, Mexico, and Nicaragua.

The shoots often display a diagonal, light band pattern marking the end of annual growth.

[3] This species is native to northwestern Costa Rica, El Salvador, Guatemala, Honduras, Mexico (Chiapas), and Nicaragua growing in dry forests at elevations from 50 to 800 meters.

First described in 1902 by Frédéric Albert Constantin Weber as Cereus aragonii, it was named in honor of Manuel Aragon, a Costa Rican statistician.

[4] In 1951, Curt Backeberg reclassified it into the genus Marshallocereus, established the year prior.