Origin and Habitat: Tunilla tilcarensisSN|3704]]SN|3704]] is endemic to Argentina, where it occurs in Jujuy, more specifically in Tilcara (extent of occurrence is 5,200 km2).
Altitude range: It grows at elevations between 2,000 and 3,000 metres above sea level.
Habitat and Ecology: This cactus grows in rocky soils in the Prepuna Region of northern Argentina. Although Tunilla tilcarensisSN|3704]]SN|3704]] has a restricted range, it is abundant and there are no major threats affecting it.

• Tunilla tilcarensis (Backeb.) D.R.Hunt & Iliff
• Airampoa tilcarensis (Backeb.) Doweld
• Opuntia tilcarensis Backeb.
• Platyopuntia soehrensii var. tilcarensis (Backeb.) F.Ritter
• Tephrocactus tilcarensis (Backeb.) G.D.Rowley

• Tunilla soehrensii (Britton & Rose) D.R.Hunt & Iliff
• Airampoa boliviensis (Backeb.) Doweld
• Opuntia boliviensis Backeb. in Backeb. & Kunth
• Opuntia multiareolata Backeb., Backeb.
• Opuntia soehrensii Britton & Rose
• Platyopuntia soehrensii (Britton & Rose) F.Ritter
• Tephrocactus soehrensii (Britton & Rose) G.D.Rowley
• Opuntia cedergreniana Backeb. in Backeb. & F.M.Knuth
• Airampoa cedergreniana
• Opuntia obliqua Backeb.
• Tunilla tilcarensis (Backeb.) D.R.Hunt & Iliff
• Airampoa tilcarensis (Backeb.) Doweld
• Opuntia tilcarensis Backeb.
• Platyopuntia soehrensii var. tilcarensis (Backeb.) F.Ritter
• Tephrocactus tilcarensis (Backeb.) G.D.Rowley

Description: Tunilla tilcarensisSN|3704]]SN|3704]], best known in cultivation as Airampoa tilcarensisSN|3706]]SN|3706]], is a low low growing cactus with flattened, semicircular stems, covered with long needle-like spines. The flowers are large and showy, yellow to red. According to Kiesling & Ferrari (2005), in habitat the boundaries between species of the genus Tunilla are not so well defined. More precisely, the boundaries are not so defined between Tunilla soehrensiiSN|3704]]SN|3699]] and Tunilla tilcarensisSN|3704]]SN|3704]], these two species are very similar (if not the same) and it is hard to tell apart one from the other, if not for the geographical provenance and they are not considered distinct. The names Tunilla tilcarensisSN|3699]]SN|3704]] is not accepted by many botanists that treat it as synonym, but it still has a value for a collector because they identify plants with particular characters.
Habit: It forms carpets usually 1 meter in diameter or less.
Derivation of specific name: “tilcarensis” For the town of San Francisco de Tilcara (usually referred to as Tilcara) in the province of Jujuy, Argentina, and the head town of the Tilcara Department.
Stem (cladodes): At first erect or ascending, finally prostrate and rooting on under-edges of growth and forming new colonies, flattened, orbicular, sometimes crescent shaped, somewhat tuberculate, very spiny, 4-6 cm long.
Leaves: Very small falling off early.
Spines: 2-12, usually 5-8, needle-like, stout, rather variable in colour, usually yellowish to brownish, erect, unequal, spreading, on most areoles, 3-7 cm long, but occasionally up to 13 cm long (see: Tunilla tilcarensisSN|3704]]SN|3704]] cv. Fuchs).
Flowers: Mostly yellow, occasionally orange or red, to 5.5 cm long
Fruits: to 2.5(-3) cm long, lacking areoles below, with some spines to 2 cm long above. Fruits split either horizontally, or vertically on the umbilicus, a character, this latter, that in Hunt et al. (2006) indicated as distinctive of T. tilcarensis.

Bibliography: Major references and further lectures
1) Demaio, P. & Kiesling, R. 2013. Tunilla tilcarensis. The IUCN Red List of Threatened Species. Version 2015.1. <www.iucnredlist.org>. Downloaded on 11 June 2015.
2) David Hunt, Nigel Taylor “The New Cactus Lexicon” DH Books, 2006
3) Edward F. Anderson “The Cactus Family” Timber Press, 2001
4) 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/August/2011
5) Roberto Kiesling, Omar E. Ferrari “100 Cactus Argentinos” Editorial Albatros, 30/June/2005
6) Urs Eggli, Leonard E. Newton “Etymological Dictionary of Succulent Plant Names” Springer Science & Business Media, 29 June 2013

Cultivation and Propagation: Tunilla tilcarensisSN|3704]]SN|3704]] is a low maintenance groundcover plant that tolerate considerable neglect and will naturalize, it is drought-tolerant; and suitable for xeriscaping.
Growing rate: It is relatively fast-growing species; in cultivation with generous irrigation it sprawls to form large low mounds in only a few years. It is suitable for hanging baskets too.
Soils: Easy to cultivate outdoor in dry, sandy or gravely, well-drained soils. May be grown in clay soils as long as drainage is good and soils do not remain wet, it is very adaptable both in acid, neutral and basic (alkaline) soils, but prefers a pH in the range 6 to 7.5.
Repotting: Use pot with good drainage.
Feeding: During the beautiful season it’s good to enrich the soil using a fertilizer rich in potassium and phosphorous, but poor in nitrogen, because this chemical element doesn’t help the development of succulent plants, making them too soft and full of water.
Watering Needs: Outdoors little or no water once established, in the green house irrigate regularly from March to october, keep fairly dry in winter, tolerate dry condition but suffer if exposed to prolonged and severe drought. A position at the base of a south-facing wall or somewhere that can be protected from winter rain is best for this plant, but is however resistant to moisture and rain.
Sun Exposure: Full sun, in semi shaded position wont produce many flowers.
Frost hardiness: They are reasonably cold hardy , tolerating temperatures down to -5° to -15° C (or even less) depending on clone, they are also quite tolerant of winter wet. (In good drained soils)
Heat Tolerance: Excellent.
Pest & diseases: No serious insect or disease problems. Watch for mealy-bugs.
Propagation: Propagated by cuttings of leaf pads at any time in the growing season. (Allow cut surface to callus over before planting).