I found this distinctively colored plant in our yard. It has the four-sided stem, opposite leaves, and just the "look" of something in the mint family. Leaf undersides are burgundy/purple and the tops of the leaves are a deep green. Younger foliage has more of a purple tone on the upper side as well. The odor when crushed is mild to nonexistent. Is this a weed, a native, or just a random plant from some scattered seed?
A picture is at:
http://davesgarden.com/community/forums/t/994563/#post_6606857.
Got a suggestion on DG that this might be some sort of Plectranthus, but looking for more specifics...
THANKS IN ADVANCE!