A distinctive plant quite different to other Rebutia, with small, soft bodies, freely offsetting and branching, and tending to spread along the ground. The photograph in the original description shows it growing over the surface of a boulder almost like a lichen. Flowers range from dark red through to pink, purple, orange, yellow and white, although I believe white forms have not been found in the wild, only in cultivation.
The description is here.
Plants of this species in the collection include:
Aylostera fabrisii JO232
Aylostera fabrisii MN135
Aylostera fabrisii WR688