Amanita cheelii

You have Amanita punctata which is a mycorrhizal fungus. That is a soil fungus that grows in association with one or more nearby plants. Often Eucalyptus trees. The tree gains extra nutrients from the fungus and in turn supplies the fungus with carbohydrates that the fungus can't manufacture because it has no chlorophyll with which to photosynthesis. You've done well in capturing the diagnostic characters of this fungus, the mouse grey coloured cap (pileus) with its flat remnant patch of universal veil and striate margin. The gills (lamellae) if you look carefully have a very fine dark line on their margin. This genus has white spores. The large sacccate cup (volva) at the base of the stem (stipe) which is the remnants of the bottom half of the universal veil - you did well in gathering that without breaking it. This species doesn't have a ring (annulus) which you often find with Amanita species. Note, a great many Cortinarius species are not blue.

I've realised there has been a name change for Amanita punctata, it is now known as Amanita cheelii! Sorry about any confusion. I've updated the name above and in the species list.