This is also known as the “African potato” but is not edible as such and is actually poisonous.
It contains anti-cancer properties and used in traditional medicine for treatment of prostate cancer, tuberculosis, bladder disorders and arthritis. While it contains sterols that are good for the immune system, they are also found in many fruits and vegetables.
Small amounts of the juice can be applied to burns and a black dye extracted from the leaves is used to darken floors.
It is a smallish plant growing maybe 40mm (13”) in height and found in grasslands.