This plant popped up in the backyard so I have let it grow to identify it but I have had no luck online finding it. I am in Tempe, Arizona so it has survived 115 degrees plus temperatures.
Looks like a Lantana. From ASU.edu
Scientific: Lantana (in the Phoenix area this is mostly either L. montevidensis or hybrid cultivars of L. montevidensis and L. camara)
It is an easy plant to maintain in your area. It is an evergreen vining perennial shrub that flowers most of the year. It's fast growing and fine in full sun, but can tolerate shade. Frost can damage it, but where you are it's unlikely to kill it.
From personal experience: Lantana can just pop up in your landscape and can be difficult to get rid of permanently.