We may have aliens in the Secret Garden. The Chilean potato vine, a vigorous small tree with deadly nightshade like flowers, has developed these flat wide stems punctuated by small nodules, pictured here. All the other branches are growing normally.
We have no idea what it is. After asking about it on Twitter, the only other reference to this strange growth that we can find on the net is on http://cohutt.com/2013/09/09/another-mutant/, where this or a similar disorder affected a sweet potato Beauregarde plant. The author says the mutated branches remind him of the 40 pin serial hard drive connectors on old PCs - they are indeed a bit like that.
Any ideas what it might be?