The type species of the genus Rebutia, and has been around in cultivation since the early 1900s. Typically dark-red flowered with a pinkish sheen. Despite being around so long, there is relatively little variation in the few cultivars. Formerly Rebutia kariusiana and R. violaciflora were included, now each given specific status by Mosti & Papini (2011).
The description is here.
Plants of this species in the collection include:
Rebutia minuscula RH1186/1