I think Citrus glauca grown in a big reverse L shape from Western QLD down to Broken Hill / Menindee near the Victorian NSW border.
Then across South Australia toward the Nullarbor.
Some Australian plants are Phosphorous sensitive, and Citrus are somewhat P sensitive, in that excess can cause Iron deficiency.
The area they grow in is pretty hot, possibly more arid woodland or Chenopod shrubland than desert. It would vary from summer rain in the Nth to winter rain in the south.
Winter temperatures can drop low, but overall they would be pretty mild.
Many Australian Citrus seedlings can be slow growers.
David, does your location get hot enough to match the wild conditions. Maybe a glasshouse etc might help ?