I have never seen a white dwarf poinciana, but the leaves look somewhat like the new ones on mine--which has orange flowers.

i found delonix elata - listed on DG site and TT. but it is not dwarf and flowers as they decline turn creamy-yellow.
i kick myself for not taking a close-up of the flower - i did not notice them. or may be they just opened on my last day of visit.
this is a very fuzzy close-up.
it is smth that looks similar to poinciana, but is not.
i was just wondering if it's unusual.

i think it's possible it's
Caesalpinia Mexicana . and it's often confused with other similar caesalpinias.
and they grow in phoenix, az.

Here is a link that might be useful: here's a post