Australia and USA don't allow seed or plant matter exchange.
Otherwise I would more than happy to send you any seed I have here. ♣
Even if Corms were sent Air mail to you.
They would probably freeze to death in the Aircraft hold during the 15 hour flight.
yes tropicanna is sterile, the only way to get one is from roots. many hybrid cannas will also be sterile. Growing a canna from seed your not garenteed to get anything like the mother plant. Infact any combination that went into making that plant you can end up with. if you want a canna that is like the mother plant only way is from a root piece.
Having said that i love growing cannas from seeds. I for example planted 8 red stripe seeds last summer and only one was the purple color the rest were green. I like that i get a bunch to choose from and pic my favorite and the ones that dont work get tossed.
I only have cannas grown from seed, since i moved to the US from canada and wasn't able to bring my collection with me. I had to start over. Seeds so far were all i had. Abutilon a member here has a great selection of seeds for sale if your interested, i've ordered some from her in the past and had great luck with them. http://growingcannasfromseed.blogspot.com/ hope that helps