Palo Verde in Bloom against the Catalina Mountains in Tucson, AZ. Photo taken Thursday, April 2, 2015. Photo by Ron Medvescek, Arizona Daily Star.

Ron Medvescek / Arizona Daily Star
There's also a species called "Desert Museum"

It's named after the Arizona-Sonora Desert Museum. According to a Los Angeles Times article, the name was created about thirty years ago when staff members at the museum began to notice thornless palo verde trees that bloomed throughout the summer.