This is the first report of this taxon from Costa Rica. The previously known southern limit was Mexico. In Costa Rica, we have collections from Guanacaste near Santa Rosa (Quercus oleoides) and Pedregal on Cerro Cacao (Q. brenesii). The spore wall is minutely pitted (below), but not to the degree seen in A. subvirens, and can be difficult to demonstrate under the microscope. The dry pileus and stipe, ±uniform cinnamon brown colors, and white to pale yellow hymenophore that becomes pinkish vinaceous is distinctive. Occasionally there are elevated ridges on the stipe and there is a tendency for yellow stains to develop near the base of the stipe.