Wedelia?

As far as I know, Wedelia acapulcensis is a Texas native, and is not found outside of the state. I also though Acmella, but that one shouldn't be in Phoenix either. You might have to post a better photo of the flower for results.

Any possibility it's Straggler Daisy?

Here is a link that might be useful: Calyptocarpus vialis

Here's another picture of this plant.
For those who live in warm areas like Phoenix, Arizona, this may be a great lawn alternative for you. It grows easy, quickly, has no thorns, you can walk on it and it comes back up quickly.

I just wonder what it is.

I think it came along as a weed when I planted some potted plants I bought from a local home improvement store, and now it has taken over my back yard. But I'm happy about it. It is so much nicer than grass.

Since plant identification is based on flower structure, we need to see a close up of a flower. . Can you post a macro shot of a blossom?

This post was edited by carol23 on Wed, Nov 26, 14 at 11:21

Hey, thanks Carol! I think it looks a lot like Straggler Daisy.

That's probably what it is.

I really like this plant. It makes a great lawn alternative.

My only camera is a smartphone, and it's not much of a camera, so I couldn't get a close-up of the flower without it being very blurry.

I believe its stagger daisy / horseherb. We have this at our office in Central Phoenix Area. Love it... Grows great under our pines and citrus. Anyone new to our office almost always asks about it...

This post is a year old and the plant has already been unambiguously named with its botanical label, Calyptocarpus vialis.