I have something similar happening with one of my MILS tubers. It had a length of stem attached to it. Now, it does have a tuber, but it is not rooting and honestly looks like it is on lifes last legs. However... In a few different places, along this dried out woody stem, there are buds forming! I think these where dorment meristems (you see the ridges where the buds are). Almost impossible to believe the thing is alive, but, it is!!

I am planning on letting them grow a little more, and then cutting them off and planting them like one would a cutting. Probably not sever it from the stem, but plant them with pieces of the stem and all.

This should take you to my question.