Aylostera (Rebutia (Digitorrebutia)) eos was originally described in Succulenta 51(2), p.2, by Walter Rausch in 1972.

Here is the text of the description of this species in the original Latin, but you should look up the original description for more details, including further details in Dutch and photographs. The English translation below is my own.

Rebulia (Digitorebutia) eos Rausch spec. nov.

Walter Rausch

Simplex, brevi-cylindrata, ad 25 mm alta et 20 mm diametiens, fusco- viridis, radice rapiformi; costis 12-13, rectis vel paulum tortis, in gibberes 4 mm longos ac latos dissolutis; areolis ovalibus, 2 mm longis, fusco- tomentosis; aculeis marginalibus 8-10, ad 6 mm longis, setosis, fusco- griseis, basi incrassata fuscis; aculeo centrali 1, ad 5 mm longo, validiore, fusco ad nigro, sursum directo.

Floribus lateralibus, 40 mm longis et 35 mm diametientibus; ovario globoso, rubiginoso, squamis brunneis, tomento albo, setis fuscis tecto; receptaculo roseo, in inferiore parte glabro, in superiore parte squamis atro-viridibus, lanceolatis, in phylla perigonii exteriora transientibus et pilis albis tecto; phyllis perigonii exterioribus albidis medio-fusco-roseo-striatis; phyllis perigonii interioribus spathulatis, cuspidatis, albido-roseis; fauce roseo-grisea; filamentis 7 mm supra ova­rium orientibus, roseis; stylo et stigmatibus (7-10) laete-viridibus.

Fructu bulbiformi, 6 mm diametiente, fusco, squamis obscurioribus, lana densa alba, setis subfuscis tecto, deliquescente. Seminibus Digitorebutiae typo.

Patria: Argentina, Jujuy apud Tafna, 3600 m ait.

Typus Rausch 333 in Herbario W.

English translation

Rebulia (Digitorebutia) eos Rausch spec. nov.

Walter Rausch

Plant single, short cylindrical, up to 25 mm high and 20 mm diameter, tap root, epidermis brownish green; ribs 12-13, straight or slightly twisted, divided into 4 mm long and wide tubercles; areoles oval, 2 mm long, with brown felt; radial spines 8-10, up to 6 mm long, brush-like, brown-grey with thickened brown base; 1 central spine, to 5 mm long, slightly stronger, brown to black, pointing upwards.

Flowers appearing on the side, 40 mm long and 35 mm diameter; ovary (pericarpel) spherical, reddish brown with dark brown scales with brown bristles and white felt; tube (receptacle) pink, scaleless at the bottom, upper part with black-green, lance-shaped scales, which gradually merge into the outer petals, with white hairs; outer flower petals (perianth) whitish with brownish-pink centre stripes; inner petals (perianth) spatulate with fine tips, whitish pink; throat rose-grey; stamens emerging 7 mm above the pericarpel, pink; style and stigmas (7-10) light green.

Fruit onion-shaped, 6 mm diameter, brown with darker scales, dense white wool and brownish bristles, becoming sparse.

Seed type of Digitorebutia

Habitat: Argentina, Jujuy near Tafna at 3600 m

Type Rausch 333 in herbarium W.