This is a great ground cover called New Zealand Brass Buttons - Leptinella (formerly Cotula) squallida. It looks like tiny ferns and makes a dense mat of 1" high foliage. It's evergreen in the more temperate regions, but otherwise perennial. It spreads quickly and tolerates part shade to sun. It's a grey-green color that turns bronzy in the fall and has tiny, somewhat inconsequential yellow flowers in summer. It's vigorous and spreads fast.

Leptinella is hardy in zones 4-10, but only evergreen in zones 9-10. In the colder zones (including Zone 8 Portland, Oregon where the photo is taken) it is semi-evergreen or deciduous

Very nice and thanx for answering our questions!