Hi, can anyone tell me what this plant is?

http://i10.tinypic.com/2qwew5s.jpg
http://i3.tinypic.com/47ipkjo.jpg

It was growing wild in southern Tanzania, and I brought some of the
seeds home. The closest thing I've found while browsing the internet
has been Solanum marginatum, White-margined Nightshade. I've had this
plant 3 and a half years without knowing exactly what it is, so I
appreciate any help. It's only ever flowered once in this time.
Thanks
Graeme