From TDMSKP Australian Outdoor Sports Guide
Lawyer Vine is the common name for Smilax australis, a rainforest based creeping vine which has sharp barbs regularly placed along its stem.
If you find yourself snagged by a lawyer vine, it is best to not try to simply pull out from the vine, as they are quite tough and hard to break and the barbs are very sharp and easily scratch quite deeply through the skin. It is best to carefully pull the barbs out of your clothing, and try to avoid being caught by any other vines as you move through the area.
Lawyer Vines make a very annoying obstacle when trying to bash a path through the bush.