The original description (of Rebutia rafaellii) was published in the Italian journal Cactus & Co., 1 (9) 2005, pp. 215 to 221.

Here is an excerpt, but you should look up the full description for more details.

Rebutia raffaellii Mosti & Papini sp. nov.

Typus – Holotypus: Argentina, Jujuy, near Tafna, WR 333c. Cult. S. Mosti, s. d. (FT)

A R. yuquinensi Rausch differt caulibus diametro maioribus (2.5-3.7 x 2.5-6 cm vice 2.5-3 x 2.4-4 cm), costis rectioribus numeroque minoribus (11 vice 12); aculeis marginalibus longioribus (0.7- 0.8 rarius ad 1 cm, vice 0.3-0.6 cm) numeroque minoribus (7, rarius 8, numquam 9 attingentibus) ab areolae centro (vice a marginibus) patentibus, basi magis incrassatis ac brunneis; segmentis perianthii lanceolato-rotundis nec spathulato-rotundis; squamis fructus longioribus ac viridioribus.

English translation

Differing from R. yuquinensis Rausch by the maximum diameter of the stems (2.5cm – 3.7cm x 2.5cm – 6cm versus 2.5cm – 3cm x 2.4cm – 4cm), less ribs (11 versus 12), radial spines longer (0.7cm – 0.8cm rarely up to 1cm, versus 0.3cm – 0.6cm), fewer spines (7, rarely 8, never 9), spreading from the centre of the areole (versus the margins), base brown and thickened; petals rounded-lanceolate not rounded-spatulate; fruit longer and greener.

Description notes

Solitary or offsetting a little, spherical, short cylindrical or cylindrical; diameter 2.5cm – 3.7cm; height 2.5cm – 6cm. Green or grey-green with slight brownish shading towards the base of the stems.

11 (-12) ribs, fairly straight. Tubercles rather pronounced and slightly flattened above. Areoles round or slightly oval; diameter ca. 2mm, with sparse whitish or very light brown wool.

7 Radial spines, sometimes 8, 0.7cm – 0.8cm rarely to 1cm in length, arising from areole centre, adpressed or leaning slightly outwards; horn coloured with slightly thickened brown base and brown apex. No central spines, or rarely 1 pointing upwards, 1cm long.

Buds spherical. Flowers 3 (-4)cm long and 3.5cm – 4.5cm wide. Flower tube light brown with dark brown scales. Petals 25-30, 1.2-2 cm long; lanceolate-round, sometimes with short point; differing shades of magenta (magenta-pink) and a brown central stripe on the upper side of the outer petals. Stamens magenta with yellow anthers. Style green with 7 pale yellow stigmas. Fruit spherical, 0.5cm diameter, reddish-brown with green scales and hair.

Cells of seed coat: convex, usually isodiametric; frequently interwoven tubular ridges on the sides, apical zone with finer and more tightly packed ridges.