Known locally as Msekese but also known as Chitimbe. It is known in English as Camel’s foot tree or Monkey bread.
From the Useful Tropical Plants Database
Piliostigma thonningii can be a deciduous or evergreen shrub or tree with a rounded crown; it can grow 3 – 15 metres tall. The short bole is often crooked.
Habitat is woodland, wooded grassland and bushland, at elevations from sea level to 1,830 metres.