I know many people like it as a ground cover, but Horse Herb has become the bain of my existence!
It is trying to take over everything and has nearly succeeded in some areas of my lawn. It keeps invading the flower beds too, and it takes so much time, effort and...yes, $$ too. I used to have a problem with oxalis but got that under control. I also have the purple oxalis which is pretty (not a weed) and is not invasive.