Pseudolithos horwoodii
Pseudolithos horwoodii is a species of succulent plant in the genus Pseudolithos. Native to arid areas of Somalia, it is a small, leafless plant up to  tall and  wide. Its growth habit is squat, unbranched, and blob-like, living up to the name of its genus which means "false stone". Its color is green to grayish brown. References

horwoodii
Flora of Somalia
Plants described in 1974