Common milkweed, Asclepias syriaca. Pale pinky-burgundy flowers. NOT butterfly milkweed, Asclepias tuberosa, which is orange-flowered and poisonous to humans.
When I met Ellen Zachos for another DUMBO picnic last week I had no idea I'd go home with foraged vegetables for dinner. She had spotted the milkweed in bloom beside the East River, and had noticed that there were buds left on some of the stalks, and generously allowed me to take those home, so that I could have a new taste for dinner. She collected a few pods, also edible.
Resembling loose broccoli flowers, the buds were blanched in boiling water, and then tossed in olive oil and a little lemon with salt and pepper. They were delicious: broccolini crossed with beans crossed with asparagus.