Origin and Habitat: Gymnocalycium damsiiSN|13319]]SN|13319]] var. centrispinum is reported from Bolivia (Western South America), in the vicinity of Roboré.
Habitat and ecology: This species occurs in relatively dense forest areas.

• Gymnocalycium damsii var. centrispinum Backeb.

• Gymnocalycium anisitsii (K.Schum.) Britton & Rose
• Echinocactus anisitsii K.Schum.
• Gymnocalycium anisitsii subs. damsii (K.Schum.) G.J.Charles
• Echinocactus damsii K.Schum.
• Gymnocalycium damsii Britton & Rose
• Gymnocalycium anisitsii subs. damsii f. cristatum hort.
• Gymnocalycium damsii f. cristatum hort.
• Gymnocalycium anisitsii subs. damsii f. monstruosum hort.
• Gymnocalycium damsii f. monstruosum hort.
• Gymnocalycium anisitsii subs. damsii f. variegata hort.
• Gymnocalycium damsii f. variegata hort.
• Gymnocalycium anisitsii var. griseopallidum H.Till & Amerh.
• Gymnocalycium griseo-pallidum Backeb.
• Gymnocalycium anisitsii var. tucavocense Backeb. ex H.Till & Amerh.
• Gymnocalycium damsii var. tucavocense Backeb.
• Gymnocalycium damsii var. boosii Amerh.
• Gymnocalycium damsii var. centrispinum Backeb.
• Gymnocalycium damsii subs. evae Halda, Horáček & Milt
• Gymnocalycium damsii var. rotundulum Backeb.
• Gymnocalycium joossensianum Britton & Rose
• Echinocactus joossensianus Boed.

• Gymnocalycium anisitsii subs. multiproliferum (P.J.Braun) P.J.Braun & Esteves
• Gymnocalycium damsii var. multiproliferum P.J.Braun

• Gymnocalycium anisitsii var. tucavocense cv. Red Form
• Gymnocalycium damsii var. tucavocense cv. Red Form

Description: Gymnocalycium damsiiSN|13319]]SN|13319]] var. centrispinum was first named in 1963 by Backeberg in reference to the long central spine that distinguish this variety. Backeberg named four varieties of Gymnocalycium damsiiSN|13319]]SN|13319]] (vars. centrispinum, rotundulum, torulosum and tucavocense). All these varieties were invalidly described, but today they are no more accepted because they only represents extreme of variation within the same polymorphic population. For example plants of var. centrispinum from seed often lack central spines whereas some plants of torulosum have them! Also in the var. tucavocense there are plants with and without central spines. This also applies to var. rotundulum, which is distinguished by it round body shape without pronounced ribs, but again plants with round bodies and more or less round ribs are intermingled with plants with acute ribs and are found within populations of the other varieties.
Stem: In culture the colour of the epidermis varies from copper to dark green (depending on sun exposure).
Flowers: Entirely white. A peculiar characteristic of var. centrispinum seems to be the long stylus protruding above the stamens, in all other G. damsii taxa the stylus is shorter and included within the anthers of the upper stamens.
Radial spines: 7.
Central spine: One, needle-like yellowish-brown to brown, about 2 cm long, occasionally up tu 7 cm long in age.

Bibliography: Major references and further lectures
1) E. W Putnam “Gymnocalyciums: Handbook No. 5.” National Cactus And Succulent Society, Smart & Co. (Printers) Ltd., Brackley, Northants. 1978
2) Von G. Frank “Gymnocalycium damsii-Formen aus Ostbolivien” KAKTEEN und andere
3) Sukkulenten 17(8): 155-158, August 1966
4) Volker Schädlich “From Santa Cruz to Puerto Suarez eastward a trip to the Bolivian lowlands until the Brazilian border” 23 - XEROPHILIA • Volume IV, No. 4 (15), December 2015
5) Pilbeam “Gymnocalycium - A collector's guide”. 1995

Cultivation and Propagation: Gymnocalycium damsiiSN|13319]]SN|13319]] var. centrispinum is a summer grower species that is easy to cultivate.
Growth rate: It is a relatively rapidly growing and easily flowering species that will make clumps given the best conditions.
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 -5 C ° C, or less for short periods).
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.