The Province of Salta in Argentina is the home of the Rebutia senilis. All the approximately 20 known species of the genus are native to northern Argentina and Bolivia.
Rebutia senilis is barely 8 cm (3 in) high and only a little less broad. The spines are many, numbering some 25, about 3 cm (l-1/2 in) long and pure white. The, usually several at one time, are carmine red and measure about 3.5 cm (1-¼ in) across. A noteworthy characteristic is that they are self-pollinating.
Various differently coloured forms of this species are often encountered in cultivation, chiefly: Rebutia senilis lilacino-rosea — with pale lilac-rose flowers; R. s. kesselringiana — with pure yellow flowers; R, s. iseliniana — with orange flowers, and R. s. aurescens – with pure red flowers.
In the wild rebutias grow on stony slopes together with grasses and low shrubs and their natural environment may be simulated in cultivation. Start with a relatively large dish and in this put low species of sedges, such as New Zealand sedges which require dry and cool conditions in winter, separating their underground roots by large flat stones. A suitable shrub to include in the arrangement is one of the lower species of Baccharis of the Compositae family. This natural-looking arrangement may be supplemented with a plant that is decorative for only a short period such as zephyranthes of the Amaryl-lidaceae family, which is often found together with cacti in semi-deserts and which flowers when the cacti are just beginning to ‘awaken’.