This is one of the many undetermined Agaricus  species that inhabit the Hawaiian
Islands. It is commonly collected in Coastal Casuarina Forests, although we have also
found it in Lowland Wet Alien Forests.  The very dark brown, subvelutinous, radially-
streaked pileus is distinctive and has lead to our common name of the brown pinwheel
Agaricus .  We welcome comments from anyone who recognizes this species.