a watched plant never...not grows?

so, i'm back from my minibreak (click here to see pics), and i'm delighted to find that my garden exploded with new growth, flowers, new critters, and, of course, weeds. i should go on minibreak more often.
garden image 6/21/06

west side of the garden 6/26/06 (click to enlarge photo)

east side of the garden 6/26/06, and the extraneous herb pots i had to plant due to lack of space

so much has occurred in the garden, i think i may need a couple posts to cover it so bear with me for a couple of days. the lettuce i cut back to 1.5 " on 6/22 regrew to the same size pre-harvest. thankfully, nothing bolted but the mint, which i spent the better half of the afternoon cutting back. i love mint, but the thought of this nature-born bush "seeding" more of my yard was too much to bear.
bolting mint

but i was too excited to step out of the car this afternoon to find this:
potted nasturtium blooming

and there is so much more! but for now, i will leave you with this. i am stumped by this ???? no particular scent or taste, and it's branching, and growing fast and tall. can anyone tell me what this is? click to enlarge photos.
???? bunch

close up of ????

???? roots