Agaricus buckmacadooi

Agaricus buckmacadooi, commonly known as Buck's agaricus,^[1] is a species of mushroom in the family Agaricaceae. It is found on the Pacific coast of North America.^[2]

Agaricus buckmacadooi was first described by Rick Kerrigan in 2016.^[3] Prior to that, it was often lumped together with A. deardorffensis and A. berryessae as Agaricus praeclareesquamosus or A. moelleri. At other times, these species were lumped together as A. placomyces. However, Kerrigan did research revealing that A. buckmacadooi, as well as A. deardorffensis and A. berryessae are in fact distinct species.^[1] Agaricus moelleri is a European species, and A. placomyces is an Eastern North American species.

The cap of Agaricus buckmacadooi is about 8-20 centimeters in diameter and is scaly^[4] and tannish brown.^[1] The cap starts out round or convex, before expanding out to broadly convex or flat. The stipe is 7-15 centimeters long and 1-4 centimeters wide, with a ring. The gills are free and start out a pale pink color, before becoming pinkish tan and finally brown with age.^[1] The flesh of this mushroom stains yellow.^[1]

Agaricus buckmacadooi is similar to A. deardorffensis and A. berryessae. All three species smell phenolic, stain yellow, and are very difficult to tell apart.^[5]

Agaricus buckmackadooi is found under douglas fir, hemlock, and coastal redwood trees in forests. As a saprophytic fungus, it breaks down decaying material.^[4]