Happy Bokeh Weedsday!
I haven't had time to key these out -- they're very common yard weeds here in the Northeastern US. Fortunately this isn't my yard, but in a nearby commercial lot.
Thanks to Marja G. -- this is Ajuga reptans, a species from Europe that is commonly grown in North America as a groundcover. It commonly escapes into yards and nearby wild areas and is considered invasive.