Our first contestant lives in my yard in various spots, but most notably on a side bed that we haven't done anything with yet. This weed (or whatever) owns this bed. It controls it. The bed belongs to it. Since I have no idea what may have been planted here before, and so little notion of what's a weed, I do not know whether to rejoice at a happy wildflower colony or, as is far more likely, weep with terror and go for the flamethrower and sow the grounds with salt.
There's a very large stand of this stuff, as I said, and the plants themselves stand a little over a foot high. I have noticed no flowers yet.
Edit: Upon being asked some good questions, here's some more info:
The leaves, when crushed, have no noticeable odor other than vague chlorophyll. The stems are genericly stemmy, the sap is identical to water.
At the base of the stem, the stem does turn reddish purple for several inches.