Thunbergia

I purchased a packet of Thumbergia seeds, very pricey at £4.50 but I love them.  I opened the packet and let out a few expletives as I counted them.  Eight seeds! 

I planted them all in a pot and, give them some credit, all eight germinated and grew.  They were on the kitchen windowsill for a couple of months before I put them outside, still in their natal pot and the soon started to flower.  

Here we are in October, the leaves are turning but they're still flowering.  Can I reap the seeds?  No chance! With all the flowers that have appeared not one seed head contains a seed.  Hummm... the seeds will cost at least a fiver next year.