Now, I never professed to be a expert at identifying plants or animals that are new to me. So, imagine my surprise (I hear you laughing heartily, those of you who live in the southwest USA), when when attempting to figure out what what tree these lovely little yellow fuzzballs belong to, that I discovered it was some kind of mesquite. Yep, our favorite bar-b-que smoking wood, also a delightful spring bloomer. But be careful, there are thorns there, check out the second photo, left side of photo.
POST SCRIPT, I have since found this page on the whitethorn acacia, and believe I may have identified this plant incorrectly.