Found this growing while weeding a long-neglected perennial bed. It has very thin, red stems that creep along the ground and cascade over the edge of the raised bed.

Anyone out there know what this is? Should I keep it or pull it?

It's Virginia Creeper (Parthenocissus vitacea)

Thicket Creeper (Parthenocissus inserta)

It's a native vine that has great bright red fall color. It's worth keeping for that alone, but it can be somewhat aggressive. If you have formal beds, it's probably not something you want. But, if your beds are more naturalistic it can be a nice component, especially if you can train it to climb a tree.

The plant appears to be stoliniferous rather than vine like. In addition, the five "leaflets" are not palmate (not uniformly divided) and have no leaflet stems (only a single leaf petiole). Petioles and stolons (or stems if I am wrong) are hairy, not glabrous. Not sure what it is, but I am confident it is not Parthenocissus vitacea or P. quinquefolia.

It's very similar to Creeping Cinquefoil, Potentilla reptans.

http://static.flickr.com/122/3...

http://www.plant-identificatio...

Possilby a Potentilla or near relative?

Potentilla canadensis is possible ..

http://www.missouriplants.com/...

http://luirig.altervista.org/s...

http://www.ncwildflower.org/in...

http://www.namethatplant.net/g...

Thank you for all the responses. JRsBugs, it does look a lot like the potentilla canadensis. I'll try to look out for those little yellow flowers.