This small, but quick-growing, genus of desert cacti from Argentina easily produces offsets from the base, and flowers while still young. The individual stems are globe-shaped and are covered in tubercles arranged in ridges with bristly, thin, white spines, 1/8 in. (2—3 mm) long, in clusters of around 20.
Pale red flowers appear in late spring around the base of the stems, giving the plant its common name, red crown cactus. They are borne over several weeks and each lasts 2—3 days. R. chrysacantha is similar to R. krainziana, which has spines in a spiral, and R. miniscula, which has shorter brown spines and masses of flowers.
Size: Spread 6 in. (15 cm) in about four years.
Light: Direct sunlight, except at noon in summer.
Temperature: Normal room; winter minimum 40°F (5°C).
Moisture: Keep the soil moist (but never wet) from spring to fall. In winter, apply only enough water to prevent the soil drying out.
Feeding: Give liquid tomato fertilizer once a month in spring and summer.
Propagation: Offsets can be cut or gently pulled off to ensure the continuation of a particular plant, but rebutias grow readily from seed, often flowering at the end of their first growing season and giving a wide range of flower colors.
Special needs: This plant can literally flower itself to death within 5—6 years, so it is wise to propagate a particular favorite from offsets before this happens.