The status of the species of Rebutia is currently uncertain; indeed the genus as defined by Anderson (2001) has been shown to be polyphyletic.[7] 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.[2] Other authorities include synonyms such as R.marsoneri, with yellow to orange flowers, in R. minuscula, giving the species a much broader range of flower colour.[8][9]
Since the early 1990s, more than two dozen additional Rebutia species, previously considered independent, have been included in this species.[10] These include the following:[11][12]
^ ab"AGM Plants - Ornamental"(PDF). Royal Horticultural Society. December 2020. p. 91. Retrieved 19 May 2021.
^Ritz, Christiane M.; Martins, Ludwig; Mecklenburg, Rainer; Goremykin, Vadim & Hellwig, Frank H. (2007), "The molecular phylogeny of Rebutia (Cactaceae) and its allies demonstrates the influence of paleogeography on the evolution of South American mountain cacti", American Journal of Botany, 94: 1321–1332, doi:10.3732/ajb.94.8.1321, PMID21636499
^Sheader, Martin (2012), "Show Reports: Summer Show South", The Alpine Gardener, 80 (1): 88–91
^ abcdeComplited David Hunt. CITES Cactaceae Checklist. (List part II: Accepted taxa). (Second edition). — London, Honorary Research Fellow, Royal Botanic Gardens Kew: 1992. 1999. — 316 s. — s.265-266
^ abcdKorotkova, N.et al. 2021, Rebutia minuscula, in Cactaceae at Caryophyllales.org. A global synthesis of species diversity in the angiosperm order Caryophyllales. Published online. Accessed: 2023 Sep 17.
^ abcdHassler, M. 2021. Rebutia minuscula World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2021. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2023 Sep 17.
^Rod & Ken Preston-Mafham, «Kakteen Atlas», Eugen Ulmer Verlag, Stuttgart, 1992, 1995, ISBN 3-8001-6582-1.
