This is a pepper-bark tree (sp. warburgia ugandensis), also known as greenheart. My uncle introduced it to me. It’s meant to be one of the most valuable medicinal plants in central Africa. One of it’s local names is omukuzannume (which means the tree that makes male maleness!). Apparently, it was over-harvested to extinction in Zimbabwe.
Just look at all these medicinal uses:
Dried bark is commonly chewed and the juice swallowed as a remedy for stomach-ache, constipation, toothache, cough, fever, muscle pains, weak joints and general body pains. It is also effective in powdered form for treating the same diseases. Fresh roots are boiled and mixed with soup for the prevention of diarrhoea. Leaf decoction baths are used as a cure for several skin diseases. The inner bark is reddish, bitter and peppery and has a variety of applications. It provides treatment for the common cold; dried and ground to a snuff it is used to clear sinuses; and it is chewed, or smoke from the burning bark inhaled, as a remedy for chest complaints. The bark, roots or leaves can be boiled in water and the decoction drunk to treat malaria, but this causes violent vomiting.
Medical notes source: AgroForestryTree Database