below is an artical on it but here is the link to the pictures of it:
http://www.csupomona.edu/~jcclark/dogs/foxtails.html
"A serious hazard for field dogs, or any dogs in the field, are the hard seed-bearing structures of some kinds of grasses, often called "foxtails". These structures have sharp points at one end, and microscopic barbs, "so that they easily move in the direction of the point, but not the other way. They "work in", but they don't "work out". They can become imbedded in the hair, especially the paws and ears, and in nostrils and even eyes. As they work their way in, they cause infection, and if not treated can sometimes be fatal. Southern California has a number of different grasses with this nasty feature, most of them originally from Mediterranean Europe, and most of them common.
The purpose of this web page is to help you identify some of the most common of these grasses in southern California. The same species are found in other parts of the Southwest, and similar species are found across North America, although sometimes with different common names. "
does that help?