Aylostera pseudominuscula (Speg.) Speg.

Regarded by some as a form of Aylostera deminuta. A little taller than spherical, with a dark green epidermis, with a slight sheen, and short, bristly, whiteish spines. The flowers tend to be smallish and dark red with a purplish cast, and white stigmas.

The original description is here.

Plants of this species in the collection include:

Aylostera pseudominuscula MN21

Aylostera pseudominuscula WR11