Rebutia (Aylostera) robustispina was first published in the Dutch journal Succulenta 56(3): p.p. 64-5 by Friedrich Ritter in 1977.

The original description in Latin is given here, together with my own English translation. Two varieties were described: the nominate, and a smaller-bodied form, named var. minor.

Rebutia robustispina Ritter spec.nov.
Plerumque solitaria, globosa, viridis, 13-50 mm crassa, radice vix rapacea; costae ca. 16, dissolutae tuberculis 2-3 mm altis; areolae fere orbiculares, lana alba vel brunneola instructae, 1-2 mm diam., 3-6 mm inter se remotae; spinae marginales 10-15, tenues, albae, lateraliter directae, 3-7 mm longae, rectae; centrales 2-6, fuscae, robustae, 10-25 mm longae, interdum deorsum pandae.
Flores 38-45 mm longi; ovarium squamis parvis, lana exigua et aliquot saetis albis instructum; stylus 10-14 mm cum tubo coalitus; sulcus nectarifer 1-2 mm longus; tubus loralis 3-4 mm longus; filamenta alba, biseriata; stylus pallidus, stigmata flaveola; petala 18-20 mm longa, 4-6 mm lata, spathulata, cinnabarina, interna ignea.
Semina 0,9 mm longa, atra, tenuiter tuberculata.
Habitat Tarija, Bolivia.
Nr. collect. FR 763.

Rebutia robustispina Ritter var. minor Ritter var.nov.
Ab var. robustispina recedit corpore minore (ad 35 mm crassa); spinis crassioribus, aliquot paucioribus, omnibus primum fuscis, postea griseis; floribus minoribus, petalis cinnabarinis vel coccineis.
Habitat Cajas, Prov. Mendez, Bolivia.
Nr. collect. FR 763 a.

English translation

Rebutia robustispina Ritter spec.nov.

Mostly solitary plant, spherical, green, 13-50mm thick, with a barely tuberous root; approx. 16 ribs, divided by 2-3mm high tubercles; areoles almost circular, provided with white or brownish wool, 1-2mm diam., 3-6mm apart; 10-15 thin, white margin spines, spreading laterally, 3-7mm long, straight; 2-6 central spines, dark brown, firm, 10-25mm long, sometimes bent downwards; flowers 38-45mm long; ovary with small scales, short wool and some white bristles; style fused with the flower tube for 10 – 14mm; nectar groove 1-2mm long; flower tube 3-4mm long; stamens white, arranged in 2 rows; style pale, stigmas yellowish; petals 18-20mm long, 4-6mm wide, spatulate, vermilion red, the inner fiery red; seeds 0.9mm long, black, slightly knobby.

Habitat Tarija, Bolivia.

Field number FR 763.

Rebutia robustispina Ritter var. minor Ritter var.nov.

Different from the var. robustispina due to a smaller plant body (up to 35 mm thick); thicker spines, somewhat less numerous, all initially dark brown, later grey; smaller flowers with vermilion or scarlet petals.

Habitat Cajas, Prov. Mendez, Bolivia.

Field number FR 763a.