Aylostera pseudoritteri was first described (as Lobivia atrovirens var. pseudoritteri) by Walter Rausch in Lobivia 85, pp. 13 & 137, in 1987.

Here is the text of the description in Latin as published, with my own English translation below. You should look up the original for further details including notes in German and colour photographs.

Lobivia atrovirens Backeberg var. pseudoritteri Rausch var. nov.

Simplex vel paulum proliferans, globosa vel paulum elongata, ad 25 mm diametiens, flavo‑viridis et violaceo‑suffusa, radice rapiformi; costis 12–13, directis, in gibberulos rotundos, 3–5 mm longos divisis; areolis ovalibus, 1.5 mm longis, albotomentosis; aculeis marginalibus 4–5 paribus et uno sursum, uno deorsum directo, ad 10 mm longis, circa corpus arcuatis et inter se contextis, fuscis, postea griseis; aculeo centrali 0.

Floribus 4 cm longis et diametientibus, ovario et receptaculo roseo, squamis viridibus et lana alba tecto; phyllis perigonii exterioribus roseis, medioviridi‑striatis; phyllis perigonii interioribus rubidis; fauce rosea, filamentis purpureis, stylo et stigmatibus (6) clare‑viridibus. Fructu globoso, 6 mm diametiente, fusco‑violaceo, lana grisea et setis albis tecto. Seminibus Lobiviae atrovirentis Backbg. modo.

Patria: Bolivia, Tarija, Abra de Sama.

Typus: Rausch 506.

English translation

Lobivia atrovirens Backeberg var. pseudoritteri Rausch var. nov.

Single to branching a little, spherical to a little elongated, up to 25mm in diameter, yellowish green and suffused with violet, tap-rooted; 12 – 13 ribs, straight, divided into round tubercles 3 – 5mm long; areoles oval, 1.5mm long, with white wool; 4 – 5 pairs of marginal spines and one pointing upwards, one pointing downwards, up to 10mm long, curved around the body and intertwined, brown, later grey, no central spines.

Flowers 4cm long and the same wide, ovary and receptacle pink, with green scales and white wool; outer petals pink with a green central stripe; inner petals red; throat pink, anthers purple, style and stigmas (6) pale green. Fruit spherical, 6mm in diameter, brownish-violet, with grey wool and white bristles. Seed as for Lobivia atrovirens Backbg.

Habitat: Bolivia, Tarija, Abra de Sama.

Type: Rausch 506.