The narrow, tubular, white flowers appear near the tips of the shoots and are rather unpleasantly scented.

[5] The first description of the species as Echinopsis mirabilis by Carlos Luis Spegazzini was published in 1905.

[3][6] The specific epithet mirabilis comes from Latin, means 'wonderful' and refers to the appearance of the species.

[citation needed] De Haas placed the species in the genus Setiechinopsis in 1940.

[3] Setiechinopsis mirabilis is distributed among lowland shrubs at 500 to 1000 meters in the Argentine provinces of Santiago del Estero, San Juan, La Rioja and Mendoza.