We cannot make an accurate identification based on your photos. There are several possibilites such as jointhead arthraxon or asiatic dayflower. They can be confusing. Here are links to Virginia Tech with information on both.
Jointhead arthraxon - A low growing grass with short wide leaves that encircle the stem and have hairs along the margins. http://oak.ppws.vt.edu/~flessner/weedguide/arahi.htm
Asiatic dayflower - broad grass like leaves and a prostrate growth habit. This plant is most likely blooming now with bright blue flowers. You will have to look in the middle of the day not in the morning or evening. http://oak.ppws.vt.edu/~flessner/weedguide/comco.htm