I can't be certain from the photo, but it looks a bit like Eragrostis spectabilis, AKA Purple Love Grass. If it is, be careful with it. It reseeds freely in my garden.

I believe it to be Hordeum jubatum, foxtail barley or squirrel tail grass. This is native to much of the western US (certainly Colorado) but is considered rather weedy......not sure how well it would work as a garden ornamental.

Here is a link that might be useful: foxtail barley

Foxtail is pretty but I wouldn't add it to my garden, especially if you have dogs, as it has unpleasant seed heads.

http://forum.smartcanucks.ca/44333-danger-dogs-foxtail-grass-please-read-if-you-have-dog-canada/ -scroll down to the 3rd post.

I'm not positive if it was the same kind, but a friend's dog had a foxtail seed in his ear (this was in MT) that required surgical removal. I try to pull the seed heads off the ones growing in my backyard b/c of the dogs.

Now if I could just figure out which grass has the super wicked seeds that are sticking the poor dogs this week...some of the nastiest I've ever seen.

Here is a link that might be useful: foxtail warning