The original description of Rebutia (Aylostera) violascens was published in Kakteen und andere Sukkulenten 28(4): 76, 1977, the journal of the Deutsche Kakteen-Gesellschaft, by Friedrich Ritter.

Here is the text in Latin as published, with my own English translation below. You should look up the original description for more details.

Rebutia violascens Ritter spec. nov.

Plerumque solitaria, in sole violascens, 2-3 cm crassa, radice valde rapacea; costae 10-13 (-16), fere dissolutae, 2-4mm altae; aerolae in summis tuberculis, 1,5-2 mm longae, 0,5 mm latae, 2-4 mm inter se remotae; spinae pectinatae, omnes marginales, lateraliter directae, 8-10, 2-5 mm longae, prima fuscae, deinde albae.

Flores profunde laterales, 3—4 cm longi ; ovarium squamis pullis, 2—3 mm longis, pilis albis et saetis albidis instructum; tubus cum stylo coalitus 2-5 mm; sulcus nectarifer tubiformis, 2-3 mm longus; tubus floralis 10-12 mm longus; filamenta rosacea; stylus viridis; stigmata 7, flaviviridia; petala oblanceolata, 18 mm longa, 6 mm lata, colore 6-7, satietate 2; semina brunneoatra, 1,2 mm longa, 0,9 mm lata, vix tuberculata.

Habitat Carmago, ad septentriones versus, Prov. Nor-Cinti, Bolivia. Collected as FR 352.

English translation

Rebutia violascens Ritter spec. nov.

Usually single, suffused with violet in the sun, 2 – 3cm thick, with a fleshy tap root; 10 – 13 (-16) ribs, almost indistinct, 2 – 4mm high; areoles at the peak of the tubercles, 1.5 – 2mm long, 0.5mm wide, 2 – 4mm between each; 8 – 10 pectinate spines, marginal only, pointing sideways, 2 – 5mm long, first brown, then white.

Flowers arising from the sides, 3 – 4mm long; ovary 2 – 3mm long with small scales, white hairs and whitish bristles; style fused with the tube for 2 – 5mm; nectary tube 2 – 3mm long; floral tube 10 – 12mm long; stamens pink; syle green; 7 stigmas, yellowish green; petals oblanceolate, 18mm long, 6mm wide, colour 6 to 7 [orange to orange-red], saturation 2 [ pastel / pale], seeds brownish black, 1.2mm long, 0.9mm wide, slightly warty.

Habitat: to the north of Camargo, Prov. Nor-Cinti, Bolivia. Type: FR 352.