Originally Posted by wildstarblazer
Looks like a hop clover to me.
I agree, it is a clover of some type. 3 round leaves. It doesn't appear to be hop clover though.
Lespedeza is much tighter growing, darker green and currently in my area, some of it is producing small lavender/purple flowers. As it matures it develops a woody type stem and is difficult to control with anything other than MSM in Bermuda lawns. KBrashears is correct. It has been an exceptional year for lespedeza. Extremely thin turf early in the year due to extreme drought of 2012 gave it all the room it needed to go crazy.
Either way, at appropriate rates, I believe MSM would handle your problem with the clover no problem as others have pointed out already.
If you are that worried about using Metsulfuron in cool season turf, I would probably use 3 way spiked with Triclopyr myself. I believe that would cure your problem as well. JMO