These Agaricus species are known to cause stomach upsets, the common theme is the stench from the base of the stem when crushed and instant chrome yellow oxidation particularly the stem butt. For those without a sense of smell there are chemical tests that can be used. I have not tried this as my sense of smell and taste are attuned to Agaricus.
Agaricus xanthodermus Sunshine Coast
Agaricus xanthodermus Tasmania
Agaricus xanthodermus Tasmania
Agaricus moelleri Sydney
Agaricus moelleri Sydney
Agaricus moelleri Sydney
Agaricus rotalis
Agaricus rotalis
Agaricus rotalis
Agaricus aff. praeclaresquamosus Tasmania
Agaricus aff. praeclaresquamosus Sunshine Coast
Agaricus aff. praeclaresquamosus Sunshine Coast
Agaricus aff. praeclaresquamosus Sunshine Coast
mushroaming 