I bought an account long polyp leather from Petco and the polyps have gotten a lot longer as I've had it. It looked similar to yours but not green, I'll post a pic when I get home. I'm not sure where the dividing line is on weeping willow cause I've seen some with crazy long polyps and some labeled as weeping willow with ones that look just kind of long. Maybe some one can weigh in on this.
Here's the polyps on mine. Definitely seen longer on weeping willow but they seemed to grow longer after I got it home and established. Good luck finding one!