This young weed to the left is in a bermudagrass lawn and is called Henbit. I took the picture October 5th. Most people dont recognize it when it is this small they only recognize it when it blooms in the spring like the picture from Virginia Tech. The purple blooms can be nice but the plant is a bad weed in lawns. So if it is germinating now and is already up in our lawns it will be slowly growing all winter and then in the spring it will take off. To control it you should work throughout the fall to kill the small germinating seedlings so that by spring your lawn is grass not Henbit!