Gymnocalycium damsii v tucavocense

All cactuses here are on sale

 Scientific name: Gymnocalycium damsii var. tucavocense Backeberg nom. inval. (Art. 8.2), Descriptiones Cactacearum Novarum 3: 6,1963

Origin: Brazil, Bolivia, Paraguay.

Conservation status: Listed in CITES appendix 2.

Habitat: G. damsii (anisitsii) grows in open areas under the protection of low bushes. It often form large groups and is extremely variable. It grows in the southern Brazil, in a loamy soil, under scrubs and little trees, mostly in a light shadow. The population seems very healthy and the number of Gymnos growing there was impressive.

Synonyms: Gymnocalycium anisitsii (K. Schumann) Britton & Rose 1922) Gymnocalycium damsii (K. Schumann 1903) Britton & Rose The Cactaceae 3: 163;  Gymnocalycium damsii var. anisitsii Katalogname, zit. in Schneekloth-Liste; Gymnocalycium tucavocense Haage SL 1992/93?; Gymnocalycium anisitsii var. tucavocaense; Gymnocalycium joossensianum; Gymnocalycium griseopallidum

Seems to be a pretty variable plant you might get some other names which are effectively the same plant.... and also not sure all plants identified as this are really this. 

Description: Solitary or freely offsetting from the areoles:

Stem:. Up to 10 cm tall , 8-15 cm in diameter colourful  and highly decorative, with characteristic horizontal clear and dark strips. The clear areas (above the areoles) are pastel-grey-pink while the dark zone (below the areoles) are Deep olive-green to brown-purple.

Spines:  Nearly useless in terms of defense.

Flowers: flowers very numerous, grow from clumps of thorns, 6 - 6.5 centimeters long.

Fruit:. Fruit inside the pod of this particular plant is a surprisingly deep and vibrant pink.

Sun Exposure: Light shade. It may tolerate bright situations  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. This plant needs plenty of space for its roots, re-potting should be done every other year or when the it has outgrown its pot. This species is particularly easy and accommodating, seldom suffer of cryptogamic diseases

Cultivation: It is a summer grower species that offers no cultivation difficulties.  Water regularly in summer (but do not overwater ) Keep this plant almost dry in winter at a minimum temperature of 0°C, prefer relatively rich substrate and  low pH  compost (if possible not limestone) otherwise growth will stop altogether. Feed with a high potassium fertilizer in summer. It is quite frost resistant if kept dry (hardy to -5° C) 

Propagation: Direct sow after last frost. (seldom produces offsets)9

Pests and deceases: This species is particularly easy and accommodating, seldom suffer of cryptogamic diseases

 Notes: Numerous publications point out that Gymnocalycium damsii is very variable, meaning it has the ability to change characteristics from plant to plant despite staying within the same species. For example, a batch of seedlings may, and are likely to be, all subtly or noticeably different to one another. Furthermore, in my experience damsii seem efficient parents for both pollinating other plants and producing their own pods of hybrid origin, especially within the muscosemineum subgroup