Similax rotundifolia
Catbrier or Greenbrier
This woody vine, with it's thorny stem can form unbelievable tangles in the forests. Seen on the Eastern Coast of the US.
The flowers are greenish white and will be in bloom in the spring.
The leaves are heart-shaped and very leathery.
Long tendrils help this weed cling and climb its way to nuisance in a landscape.
Digging deep may help to eradicate the vine.
Tip: When transplanting - hardening off your plant will save headaches later on.