Origin and Habitat: Argentina, Salta, San Felipe – La Angostura
Altitude: 1733 metres above sea level.
Habitat and ecology: Gymnocalycium spegazziniiSN|996]]SN|996]] ssp. Sarkae grows isolated from other populations, on gentle slopes with sparse vegetation of shrubs and grasses on moulded stony or sandy soil. It occurs only sporadically. Rainfall here often are long lasting.

• Gymnocalycium spegazzinii subs. sarkae Halda & Milt

• Gymnocalycium spegazzinii Britton & Rose
• Echinocactus loricatus Speg.
• Gymnocalycium loricatum Speg.
• Gymnocalycium spegazzinii subs. armatum (F.Ritter) Halda & Šorma
• Gymnocalycium armatum F.Ritter
• Gymnocalycium cardenasianum f. armatum (F.Ritter) H.Till & Amerh.
• Gymnocalycium spegazzinii var. armatum (F.Ritter) Slaba & Šorma
• Gymnocalycium spegazzinii subs. fiambalense
• Gymnocalycium spegazzinii var. horizonthalonium Backeb.
• Gymnocalycium horizonthalonium Frič ex Kreuz.
• Gymnocalycium spegazzinii var. major Backeb.
• Gymnocalycium spegazzinii var. punillense H.Till & W.Till
• Gymnocalycium spegazzinii var. recii Milt
• Gymnocalycium spegazzinii subs. sarkae Halda & Milt
• Gymnocalycium spegazzinii var. unguispinum Slaba

• Gymnocalycium spegazzinii subs. cardenasianum (F.Ritter) R.Kiesling & D.Metzing
• Gymnocalycium cardenasianum F.Ritter

• Gymnocalycium cardenasianum cv. Japanese Selection

Description: Gymnocalycium spegazziniiSN|996]]SN|996]] ssp. sarkae is a very distinctive naturally occurring variant of Gymnocalycium spegazziniiSN|996]]SN|996]] with different seeds, darker purple-brown epidermis and long spidery brown spines.
Habit: It is a flattened solitary cactus with very characteristic spines pointing sideways or downward.
Stem: Noticeably flatten, in nature it is partially underground, dark-violet, grey-violet or brown, 80-150 mm in diameter (occasionally individual specimens may reach up to 25 cm in diameter). Apex depressed an woolly. Will not offset.
Ribs: 8-12 broad an low, evenly subdivided in confluent tubercle, 15 mm long about 20 mm wide at the base, angular and somewhat keeled.
Areoles: Elongate woolly at first white, later turning grey.
Central spine: Absent.
Radial spines: 3-9 spidery in shape, typically recurved, pointing sidewards and downward, greyish or brownish, depressed against the body and most attractive.
Flowers: Funnel-shaped on the plant apex 45 mm long, 50 mm in diameter whitish to pink with red throat. Outer tepals spatulated abaxially scaly, 3-7 mm long and 4-6 mm wide olive green. Inner tepals smaller 20 to 13 mm wide and 35 mm long and basally crimson coloured (red throated). Tube up to 20 mm long and 10 mm in diameter, olive green. Ovary up 7 mm in diameter and 20 mm length. Filament crimson or violet, anthers pale-yellow. Pistil 15 mm long, stigma-lobes milky white. Scales on the ovary few and broad.
Blooming season: Flowers are produced in late spring and remain open for up to twelve days.
Fruits: Elonged, naked, up to 30 mm long and 15 mm in diameter, olive green or purple, covered with bluish pruine, scales edged in pink. Splitting open at maturity with 1-2 longitudinal cracks. Pulp whitish.
Seeds: Of the microsemineum type about 1 mm long and 0.8 mm in diameter, shallowly tuberculate, testa regular, hilum concave.

Bibliography: Major references and further lectures
1) Ivan Milt , říjen 2007 "Gymnokalycia podrodu Microsemineum Schütz, sectio Loricata Schütz" <http://www.carciton.cz/kaktusy/clanky9.htm>. Downloaded on 25 February 2014.
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) N. L. Britton, J. N. Rose “The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family.” Volume 4, The Carnegie Institution of Washington, Washington 1923
5) Curt Backeberg “Die Cactaceae: Handbuch der Kakteenkunde” Gustav Fischer Verlag, Stuttgart New York 1982–1985
6) John Borg “Cacti: a gardener's handbook for their identification and cultivation” Blandford P., 1970
7) Méndez, E., Kiesling, R. & Ortega-Baes, P. 2013. Gymnocalycium spegazzinii. In: IUCN 2013. "IUCN Red List of Threatened Species." Version 2013.2. <www.iucnredlist.org>. Downloaded on 15 January 2014.
8) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001

Cultivation and Propagation: Gymnocalycium spegazziniiSN|996]]SN|996]] is a summer grower species that is easy to cultivate.
Growth rate: It is a slow growing and easily flowering species.
Soils: It likes very porous standard cactus mix soil. Prefer a low pH compost, avoid substrata rich in limestone; otherwise growth will stop altogether.
Repotting: This plant needs plenty of space for its roots, repotting should be done every other year or when the it has outgrown its pot. Use pot with good drainage.
Watering: Needs moderate to copious waterings in summer, but do not overwater (Rot prone), keep dry in winter at a minimum temperature of 0°C.
Fertilization: Feed with a high potassium fertilizer in summer.
Hardiness: Reputedly resistant to frost if kept on the dry side prior to, and during, cold weather (hardy to -12 C ° C, or less for short periods), but for safe cultivation it is best to avoid freezing temperatures.
Exposition: The plant tolerates extremely bright situations but enjoys filtered sunlight or afternoon shade, inside it needs bright light, and some direct sun. Tends to bronze in strong light, which encourages flowering and heavy spine production, but is likely to suffer from sun scorch or stunted growth if over exposed to direct sunlight during the hottest part of the day in summer.
Uses: It is an excellent plant for container growing. It always looks good and stays small. It look fine in a cold greenhouse and frame or outdoor in a rockery.
Pests & diseases: It may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for:
- Red spiders: Red spiders may be effectively rubbed up by watering the plants from above.
- Mealy bugs: Mealy bugs occasionally develop aerial into the new growth among the wool with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects.
- Scales: Scales are rarely a problem.
- Rot: This species is particularly easy and accommodating, seldom suffer of cryptogamic diseases. Rot it is only a minor problem with gymnocalyciums if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Propagation: Division, direct sow after last frost. Seeds germinate in 7-14 days at 21-27° C in spring, remove gradually the glass cover as soon the plants will be well rooted (ca 1-2 weeks) and keep ventilated, no full sun for young plants! To make a cutting twist off a branch and permit it to dry out a couple of weeks, lay it on the soil and insert the stem end partially into the soil. Try to keep the cutting somewhat upright so that the roots are able to grow downward.