I am pretty sure we are too cold for them here, and I've never heard of one growing outdoors anywhere in OK. They likely would grow in some of the frost-free parts of the Gulf coast or California or similar frost-free settings. It is my understanding they are native to the wet tropical rain forest (frost-free) areas in Australia, and we are kinda short of frost-free areas here, unfortunately.

I imagine you could keep one alive for a few years in a large container that you carry inside any time frost is even a slim possibility. I grow citrus trees that way---outdoors most of the time, but carried indoors if cold threatens.

If you're interested in experimenting, you could order seeds from GV, plant them in containers, and try growing in a container for a few years to see how it goes. If you succeed, though, at some point the container-grown tree will outgrow your house, unless you have high vaulted ceilings.

I'll link the seed source I'm aware of below. You also could look at the website of Plant Delights Nursery. If any nursery in this country would have them available as trees instead of seeds, I imagine it would be Plant Delights.

I have tried a few Australian native plants here, without success. Nothing I've tried yet will tolerate our colder weather.

Dawn

Here is a link that might be useful: Ivory Curl Tree Seed at Georgia Vines