Oh, dear...I found it and it's invasive.chameleon-plants-gone-wild

I have heard nothing but regret from those who planted this. I would get rid of it asap and keep a vigilant eye out for sprouts.

Looks like Houttuynia cordite to me, Jane... it's a runner and a thug, but people mistakenly buy it because the leaves turn red when it's grown in more sun. Houttuynia becomes a wild mat of aggression, growing around and around itself and spreading via underground runners. Once it takes hold, it owns your yard.