Came across this interesting sounding tree in a gardening book , though not strictly South African as it comes from Zimbabwe and Malawi it is evidently naturalised to S.A.

Decorative small tree 3 metres but double this in optimum conditions. Glossy green leaves , greyish green on undersides , margins often wavy. Attractive clusters of white flowers mid Spring to Summer. Flowers somewhat resemble that of jasmine and have a sweet scent rather like jasmine. (Does not state but probably referring to Jasminium polyanthum). Slow growing and does not like severe frost. Can tolerate dry conditions but does best when well watered and regularly.

Must try to get one of these.