Lobivia (Aylostera) nigricans was first described in Beiträge zum Sukkulentenkunde und Pflege, p. 51, by Willy Wessner, in 1940. Lobivia (Aylostera) nigricans var. albispina (ssp. albispina) was first described in Lobivia 85, pp. 100 & 142, by Walter Rausch in 1987.

Here are the descriptions for both, in Latin as published, with my own English translations below. The descriptions themselves are very brief and something of a formality- there is much more detail provided in the accompanying text which is not reproduced here. You should look up the originals for extensive further notes in German and photographs.

Lobivia nigricans Wessner sp. nov. Von Wilhelm Wessner, Mannheim

Caulis simplex vel pluri-capitatus, breviter cylindraceus, mollis, in statu juvenili saturate viridis, dein fuscus et violacee nitens. Costae 11, vix sufflexuosae, in tuberculis conicis dissolutae. Aculei 8—12, radiales pectinatim dispositi, primum fulvi dein canescentes. Flores laxe infundibuliformes, brevissimi, phyllis perigonii curtissimis rutilisque. Stamina rosea solum ex fauce. Stylus notabile crassus, cum tubo 3 mm in unum confundus. Fructus baccae similis et maturans subsiccus.

Lobivia nigricans Wessner var. albispina Rausch var. nov.

Simplex vel paulum proliferans, globosa, ad 35 mm diametiens, clare­glauca, radice rapiformi; costis ca. 12, rectis vel paululum spiraliter tortis, in gibberes 7 mm longos, rotundos, subver­ rucosos divisis; areolis ovalibus, 5 mm longis, albo­tomentosis; aculeis marginalibus 5 paribus et 1 deorsum directo, divaricatis ad accumbentibus, plus minusve inter se contextis, ad 6 mm longis, setosis; aculeo centrali 0.

Floribus 30 mm longis et 25mm diametientibus, ovario et receptaculo clare­viridi, squamis obscure­viridibus, lana et setis albis tecto; phyllis perigonii exterioribus rotundis, tenui­acuminatis, viridibus, roseo­marginatis; phyllis perigonii interioribus rotundis, ex rubro subnigris, nitidis; stylo et receptaculo dimidio connato; fauce 4 mm tantum longa, alba, filamentis albis, stylo et stigmatibus (5) clare­viridibus. Fructu seminibusque Lobiviae nigricantis Wessn. modo.

Patria: Argentina, lta, Escoype, 2.700 m, alt. Typus: Rausch 771

Lobivia nigricans Wessner sp. nov. Von Wilhelm Wessner, Mannheim

Body single to multi-headed, short cylindrical, soft, bright green when young, then darker with a violet sheen. Ribs 11, hardly flexed, broken up into conical tubercles. 8 – 12 radial spines arranged pectinately, first dark then greyish. Flowers loosely trumpet-shaped, short, red. Stamens pink, emerging only from the throat. Style noticably thick, fused with the tube for 3 mm. Fruit and seed drying when ripe.

Lobivia nigricans Wessner var. albispina Rausch var. nov.

Single to branching a little, spherical, up to 35 mm diameter, lightly glaucous, tap-rooted; ca. 12 ribs, straight to spiralling a little, divided into round tubercles 7 mm long, somewhat wart-like; areoles oval, 5 mm long, with white wool; 5 pairs of marginal spines and 1 pointing downwards, spreading and flattened, more or less intertwined, up to 6 mm long, bristly, no central spines.

Flowers 30 mm long and 25 mm wide, ovary and receptacle light green with dull green scales, covered in white wool and bristles; outer petals round, with a small point, green with pink edges; inner petals round, dark red, bright; style and receptacle half connected; throat only 4 mm long, white, with white anthers, light green style and stigmas (5). Fruit and seeds as for Lobivia nigricans Wessn.