Can someone tell me what this is. It's growing in a garden in Arizona

You get extra credit for telling us where you saw it, but in this case it was
unnecessary. The plant is lantana, scientific name Lantana camara. It is sold
as an annual in colder climates, a houseplant, or a garden plant in the South.
But be warned. In warm climates it is extremely tenacious and invasive. There
are named cultivars with different colored flowers.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)