|Rebutia minuscula, typ.|
The status of the species of Rebutia is currently uncertain; indeed the genus as defined by Anderson (2001) has been shown to be polyphyletic. Anderson describes R. minuscula as consisting of globe-shaped stems with a diameter of up to 5 cm (2 in), forming large clusters. The stem has 16-20 ribs with small but distinct tubercles ("bumps"). Each areole produces 25-30 fine whitish spines, 1-3 mm (0.0-0.1 in) long. As in other species of Rebutia, the flowers are not produced at the top of the stem, but from around the base. They are red, up to 4 cm (1.6 in) long. Other sources include species such as R. marsoneri with yellow to orange flowers in R. minuscula, giving the species a much broader range of flower colour.
Rebutia minuscula K. Sch.
Schumann, Karl Moritz; Monatsschr. f. Kakt.-Kunde, 5: 102, 1895