Origin and Habitat: Garden origin. The natural species comes from a small area in the province of Catamarca (Argentina) at elevations of 2,500 to 3,300 metres above sea level.

• Maihueniopsis bonnieae cv. Inermis
• Opuntia bonnieae f. ineermis hort.
• Puna bonnieae f. inermis hort.

• Maihueniopsis bonnieae (D.J.Ferguson & R.Kiesling) E.F.Anderson
• Opuntia bonnieae (D.J.Ferguson & R.Kiesling) Halda & Janeba
• Puna bonnieae D.J.Ferguson & R.Kiesling
• Tephrocactus bonnieae (D.J.Ferguson & R.Kiesling) Stuppy

• Maihueniopsis bonnieae cv. Inermis
• Opuntia bonnieae f. ineermis hort.
• Puna bonnieae f. inermis hort.

Description: Maihueniopsis bonnieaeSN|1024]]SN|1024]] cv. inermis, best known in cultivation as Puna bonnieaeSN|1023]]SN|1023]] f. inermis, is a lovely spineless form (without spines). In the wild plants have 9 to 20 very short spines, flattened, radiating and slightly bent over the stem and the spineless form is very uncommon. This plant is smooth and harmless. A particularity of Maihueniopsis bonnieaeSN|1024]]SN|1024]] cv. inermis is that the flower are chameleons. When a flower start opening its petals are a pale honey-yellow, but they darken ageing. On the second day, before fading, the petals take a rich tan-rose colouration. Occasionally yellow and pink flowers occur together.

Bibliography: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) David R. Hunt “Studies in the Opuntioideae (Cactaceae)” D. Hunt, 2002
3) James Cullen, Sabina G. Knees, H. Suzanne Cubey "The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass" Cambridge University Press, 11/Aug/2011
4) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
5) Demaio, P., Kiesling, R., Trevisson, M. & Perea, M. 2013. Tephrocactus bonnieae. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 19 May 2015.

Cultivation and Propagation: This mountain cactus - because of the elongated fat taproot - necessitate deep pots and a well drained mineral potting mix. They need a sufficient amount of air.
Watering Needs: They are susceptible to overwatering, but need enough water during vegetation.
Frost Tolerance: They tolerate light frost -5 (-10) °C. Need to be kept in a cool place during winter rest this is important for the flowers as well as for their health. Without this cool winter period they normally wont get many buds.
Sun Exposure: Need a good amount of sun.
Propagation: Usually propagated by cuttings and grafting. Grafted plants in culture are most common and sprout strongly. But it is also feasible to root them but they grow much slower on their own roots and takes various years prior to they bloom.