These are grass trees (Xanthorrhoea spp.)– great name and great description. They are unique to Australia. They are drought and fire resistant. In bushfires the only thing left is a blackened stump but the plant can regrow from that. We have seen ones in flower, when they produce a long spike that turns brown and releases seeds. 

These were in the Kondalilla National Park.

 

 

You can get whole areas of these plants. These were intermingled with gum trees around the Glass House Mountains Lookout. Spot the fruiting body.  RHS fruiting head from Noosa National Park.