Echinopsis mamillosa, synonym Lobivia mamillosa, is a species of cactus from Bolivia and northwest Argentina.
Echinopsis mamillosa has a solitary growth habit, with globe-shaped stems up to tall. The stems are dark green, with a diameter of up across, and have 13âÂÂ17 deep ribs, formed into tubercles. The rounded areoles are spaced up to and produce yellowish spines with brown tips, the one to four central spines being up to long and the 8âÂÂ12 radial spines long. The flowers are white with rose tips. They are large in relation to the diameter of the stems, up to across and long.
Echinopsis mamillosa was first described in 1907 by the German botanist Max Gürke. It was transferred to the genus Lobivia by Boris Oliver Schlumpberger in 2012. , Plants of the World Online accepted the earlier placement in Echinopsis.
Two subspecies have been recognized. Subspecies mamillosa is shorter (typically only up to tall) with 17 ribs. Subspecies silvatica is taller and has fewer ribs. , neither is recognized by Plants of the World Online.
Lobivia mamillosa is widespread in the Bolivian departments of Chuquisaca and Tarija at altitudes of 1500 to 3000 meters.