Photos 4 and 5 compares A. micromegathus and A. semotus side-by-side. The habitat is in-situ for A. micromegathus only. The A. micromegathus were found on an open, sloped trailside mostly carpeted in Douglas-Fir needles with scattered grassy tufts and sprouting oak stumps.
The A. semotus were found in a layer of oak leaves on level ground near a grassy area.
Notice the differences in size and stature, pileus color, and intensity of staining (oranger and more pervasive in A. semotus). Another interesting feature to pay attention to is the strong orange color at the juncture of the stipe and lamellae in A. micromegathus (photos 2 and 3).
The buttons can be differentiated by the color, shape, and texture of the pileus, staining reactions, shape of the base, presence of copious mycelial cords, and the scurfiness of the stipe below the annulus.