Mysterious Tendrils

So I'm not really sure what this vegetable is, but I thought that such a mysterious and fabulous day as Leap Day deserved something equally special. I took this picture in Hanoi, Vietnam last summer before traveling down to Saigon for my brother's wedding. We were eating bun cha, a dish that consists of grilled pork(ish) meatballs dunked in a bowl of fish sauce (nuoc mam), vermicelli noodles, and assorted greens. These tendrils came on the greens plate along with mint leaves, Chinese basil, and other anonymous herbs. Maybe the picture below will help someone figure out what these tendrils are. The food was amazing. Unfortunately, my cousin's Belgian friend Tim got sick afterwards, a cautionary reminder of the risks of street food. I did my own stint of bathroom time in Hong Kong back in '97, and my iron stomach has conquered over all potentially harmful digestive beasties ever since. (Knock on wood, eek!)