In article m,
Cereoid+10 wrote:
Also consider that many species of Solanum have fruit that are berries eaten
by birds and may be carried long distances. Also the seeds are often
imbedded in a mucilaginous pulp that can stick to the beaks and feet of
birds.

And then the bird flies from South America to Australia...

I like the floating eggplant theory better, myself, if I can't have the
'veggies of Gondwanaland' one. Btw, IIRC most birds in Madagascar are
endemics, as was almost everything in Madagascar until recently.