Hi Grafted,
There are three that come to mind:
Botanical Wonder, Ivy Tree - x Fatshedera lizei
http://aggie-horticulture.tamu.edu/i...atshedera.html
Tree Ivy, Japanese Aralia - Fatsia japonica
http://aggie-horticulture.tamu.edu/i...fatsiajap.html
Hawaiian Schefflera, Schefflera (this one has some variegation on the lower leaves) - Schefflera arboricola
http://aggie-horticulture.tamu.edu/i...fflerahaw.html
If those aren't your plant, take a look here to see if you can id your plant.
http://aggie-horticulture.tamu.edu/i...leryindex.html
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.