Rhaphidophora juvenile

 I was stopped dead at the track when I saw this greyish green thing creeping up the tree .....

 

This is the juvenile form of Rhaphidophora (korthalsii ?) - often called a shingle plant as the leaves flatten and wrap tightly around tree trunks. As they climb higher, the plant changes to adult foliage whereby the leaf stalk elongates (hence hoisting the leaf blade away from the host tree) and the leaves splits bilaterally from the main vein and look rather like those of Calamus rattan, minus the spines of course. If indeed it is R. kothalsii, then even the adult form will also be rather variable.