Mystery plant in bed of chaos

With my ongoing experimental urban garden, this one bed was left to go wild. I was too busy to deal with it and luckily the rain was enough to keep it happily watered. No thinning was done. Carrots, beets, peas, and tatsoy were planted. The tatsoy seeds turned out to actually be regular bok choy (which is gone to seed now) and there are many, many unexpected plants sprung up in the mix. The most recognizable ones have to be from my home-made (and apparently not hot enough) compost... tons of tomato plants. They are blooming now and I've left them mostly to see what kind they are, but they're falling over and threatening to go wild, so will have to be tamed soon. Check out the chaos and crowdedness in the pic below. The yellow blossoms on the right are the bok choy (I'll harvest the seeds for next time), and the peas in theback growing over the homemade trellis have pretty white and purple blossoms.

So far I have harvested about 4 beets (posed below next to the second batch of home brew for fun). The beets were tasty but his second batch of homebrew is much more something to write home about. Lighter in color and less hoppy which makes for an ideal beer for me. Super yummy. I hope he makes more soon!

I did try to pull weeds out of the chaos patch as things were growing up, but I wasn't exactly sure what is what. Case and point is this really tall plant with an interesting set of blossoms. I don't think I've ever seen anything like it, which of course means I have to let it grow more so it can show it's true colors. What type of plant/weed do you think it is?  Will let you know more after it blooms...