Hardy Geranium or Aggressive Weed?

Mistaken identity seems to be a running theme with me these days.

While finally tackling the seemingly Herculean task of finally weeding the side garden, I noticed that what I have thus far believed to be a geranium was running rampant and spreading itself all over the place.

Full disclosure:  before I settled on “geranium,” I wondered if this particular plant might be one of the blue aquilegia from seeds I planted nearby last fall or possibly a bleeding heart  (Didn’t I plant one there my first summer here, gosh darn it?  And where did IT go?)  Sigh.

I thought it looked like a hardy geranium I had bought and planted across the driveway…it had lovely purple flowers last year and the leaves do indeed look similar…I don’t remember planting this particular plant, though, and I’m starting to wonder if it might be a plain old weed.  One that is spreading.  I pulled up many of the little babies that were popping up left and right but saved the big plant in hopes of figuring it out.

Last year I let several weeds grow happily nearly all summer long just because I wasn’t sure what they were and wanted to give them time to see who they became before ripping them out.  Nine times out of ten they were weeds.

In case it rings any bells for any of you, I’m including a few photos of the current culprit: (again with the camera phone!  Sorry!)

close up of Mystery Plant stem

close up of Mystery Plant leaf

Mystery plant seems to grow in a mound. This one is about a foot tall.

I am pretty sure that my aquilegia seeds DID come up behind this plant and that these are the young columbines here:

Aquilegia?

The leaves of this plant are kind of similar in size and shape to the Mystery Plant, but I’m pretty sure this one is Aquilegia…at least it came up right where the marker says I planted seeds! (See, I do mark *some* things now and then…trying to get better at this!)

Any ideas?  Is it geranium?