I was thinking it looked like variegated goutweed, Aegopodium:
Bishop's Weed (Aegopodium podagraria 'Variegatum')
If Susan doesn't think this is it maybe we could get a picture of just the groundcover to try and identify it? If that's what it is, it is very aggressive.
When I Googled "Devil's Weed" the results I got were Datura stramonium. Pretty sure it wouldn't be that! Goutweed is sometimes called Bishop's weed.
