The botanical name for this shrub is Brunsfelsia. It is not native to South Africa but does very well all over the country and is a very common garden shrub. It is covered with masses of medium to small flowers which are white , a lilac shade and purplish , hence its name as the flowers turn into the 3 differents colours. The flowers have a lovely fragrance. There is also one which has much larger flowers. They are fairly slow growing , I had one which reached abour 2.5 metres high in a house I previously stayed in. They can withstand a fair degree of frost.
They like full sun or semi shade. I have never seen them grown indoors but maybe you should experiment. I am amazed at the plants that Americans over winter or even grow indoors , things that here we could never imagine could be kept indoors.
There seem to be American suppliers of plants and seeds , try searching on Brunsfelsia and also Brunfelsia on Google.

There is a HUGE one in the greenhouse at Bellingrath Gardens right out of Mobile, Alabama-I love that plant, everytime I go to the gardens to see it,the scent---like honey, to me, just overwhelms me.

Thanks for the info. Out of curiousity, does anyone know where it is native if not SA?

Just in case anyone else is interested...after googling brunfelsia I found this site. It says the plant is native to Brazil.

Here is a link that might be useful: Floridata - Yesterday, Today & Tomorrow

It grows quite well in Houston, TX.