G. ritterianum has attractive stems and freely produces nice satiny white or pink flowers with rosy throats. This plant is still rare in collections, but, like many of its genus, it is easy to cultivate.

Description:  It is a variable small cactus, usually solitary.
Stem: Discoidal  up to 8 cm in diameter, clear grey-green, that tinges reddish in full sun.
Ribs: Divided  in  pronounced "chin"-like tubercles.
Spines: Long, white, yellow or pink/brown, curved against the plants body.
Central spine: None, or  sometimes one, straight, rigid.
Flowers: Near the apex, usually satiny white with rosy throats, but also white, pink or red, appearing recurrently from April to autumn.

Cultivation: It is a summer-growing species that offers no cultivation difficulty.  Water regularly in summer (but do not over-water).  Keep rather dry in winter.  Feed with a high potassium fertilizer  in summer.   Hardy as low as   -5° C (or less) if  kept dry.   Sun Exposure: Light shade.

Propagation: Direct sow after last frost, or offsets

Conservation status: Listed in CITES appendix 2.
 

• Gymnocalycium riteranum
• Gymnocalycium famatimensis Rausch nom. nud.

Origin:  Argentina (La Rioja)

Etymology:  Ritter and Rausch are two explorers who played major roles in finding and cataloging the cacti of South America . With this species, one commemorates the other.