Agaricus xanthodermus Yellow Stainer - POISONOUS - often confused with Field Mushroom Agaricus campestris. NOTE yellow stain when stem crushed - but NOT always.
Becoming more widespread. In open grassy area.
The stalk of this Grass Tree (Xanthorrhoea spp.)seems to be suffering from vertigo?
These were all burnt in bush fires last year (2005), which causes them to flower.
Brisbane Ranges National Park, near Anakie, Victoria.