Pyrrosia sheareri
Pyrrosia sheareri with Mark for scale
The fronds can reach up to 60 - 75cm, although ours hasn't reached this yet, the new growth is a lighter green before the mature leaves darken with a glossy almost leathery texture. Apparently it is fond of a free draining humus rich soil, we have grown ours in a pot and it seems quite happy so far.Pyrrosia sheareri
I'm tempted to try and divide this, but as its looking so good and it has a reputation for being tricky to propagate, we may leave it for a while longer yet. Gaz