: It is found in the provinces of La Rioja and Salta, Argentina.
Habitat: This species grows and blooms in a very dry environment on rocky soil, where few other plants can survive.

• Tephrocactus alexanderi (Britton & Rose) Backeb.
• Opuntia alexanderi Britton & Rose

• Tephrocactus alexanderi (Britton & Rose) Backeb.
• Opuntia alexanderi Britton & Rose
• Tephrocactus alexanderi var. bruchii (Speg.) Backeb.
• Opuntia alexanderi var. bruchii (Speg.) G.D.Rowley
• Opuntia bruchii Speg.
• Tephrocactus bruchii (Speg.) Backeb.
• Tephrocactus alexanderi var. subsphaericus (Backeb.) Backeb.
• Opuntia alexanderi var. subsphaerica (Backeb.) G.D.Rowley
• Tephrocactus subsphaericus Backeb.
• Tephrocactus alexanderi subvar. brachyacanthus (Speg.) Backeb.
• Opuntia bruchii f. brachyacantha Speg.
• Tephrocactus alexanderi subvar. macranthus (Speg.) Backeb.
• Opuntia bruchii f. macracantha Speg.
• Tephrocactus halophilus (Speg.) Backeb.
• Opuntia halophila Speg.
• Tephrocactus microsphaericus Backeb.
• Tephrocactus riojanus (Hosseus) Backeb.
• Opuntia riojana Hosseus in Backeb. & F.M.Knuth

: Tephrocactus alexanderiSN|22328]]SN|22328]] is a small low depressed or erect succulent plant with some spherical branches forming spiny cushions.
Stem (segments): 2,5-5 cm long, 2 to 3 cm thick, globose, egg-shaped or shortly cylindrical, greyish green tuberculate, covered with spines and readily detached.
Areoles: Small, round, closely set 30-60 or more per segment and extending to base, most with spines.
Spines: 4 to 15, up to 4 cm long, white below, dark above or with black tips, fading to dull grey as the stems age, scurfy-pubescent even in age, straight, erect or pointing downward, more or less flexible, spreading, interlocking mostly thin a few stout.
Flowers: Large pinkish-white. Pericarpels bristly above.
Fruit: Dry, thin walled, red, obovoid, 2 cm. long, not spiny, but upper areoles bearing 2 to 8 long, white, erect, fine bristles to 1 cm overtopping the fruit; umbilicus of fruit depressed.
Seed: White, 5 to 6 mm broad.

: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) 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
3) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
4) Nathaniel Lord Britton, Joseph Nelson Rose “The Cactaceae: Descriptions and Illustrations of Plants of the Cactus Family” Volume 3, 1922

: Tephrocactus alexanderiSN|22328]]SN|22328]] is susceptible to overwatering, but need enough water during the growing season. This mountain cactus - because of the elongated fat taproot - necessitate deep pots and a well drained mineral potting mix. It prefers a full sun exposure, but should be protected from excessive heat and sun in summer.
Frost Tolerance: They tolerate light frost -5 (-10) °C.
Remarks: 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. Keep dry in winter to avoid rot. Need a sufficient amount of air.
Propagation: Seeds are extremely difficult to germinate. Best reproduced from rooted cuttings. Grafting is often used to speed growth rate and to create a back-up for plants in collection.