This is an unusual fern in that it is a climber.
It can form large clumps like an inpenetrable curtain of tangled stipes - each of those long thin twisting "stems" are actually a stipe, meaning that this fern has the longest leaves in the world. Those oblong-shaped "leaves" are "pinnae" ie only part of the fern frond.
The stipes are extremely tough, especially when dry - dont try busting your way through this stuff!
It is also known as "Mangmange" and "Bushman's Mattress". The dead stipes, chopped up, make good fire-lighting material - so I'm told. (Just make sure you follow any fire-lighting restrictions!)