Stachys byzantina or Lamb's Ears. It's the texture of the leaves that gave it its common name.
If you touch the leaves they feel just like soft fir, while they are shaped like a lambs ear.
This hardy groundcover is made up of a dense cover of very softly hairy leaves that give it a whitish/silver appearance.
While it does flower, they are usually removed because this is more of a foliage groundcover.
This is a great groundcover that provides a thick dense cover and is very drought tolerant.
Other varieties include: "Big Ears" has has larger, even softer leaves.