In warm, moist seasons The Prince, Agaricus augustus, appears in June and usually can be found into October. While it does occur in forested areas, it is most commonly found in composted areas, gardens, lawns, and along road sides, usually in the open, sometimes producing successive crops in the same place if the substrate remains moist. The caps are whitish to light tan with brownish to yellowish brown flat scales, and the surface stains yellow then orange-brown when bruised. The stipe is white to slightly creamy or brownish, usually scruffy to shaggy on the lower portion, and the base is often enlarged. The gills are closely packed and cream-white to dull rose color and become dark chocolate brown from the spores when mature. A whitish, somewhat fragile membranous veil covers the gills at first, as the cap expands it leaves a ring on the stipe or flaps of tissue on the cap edge. This handsome, often large mushroom (caps can reach a foot across and stipes a similar length), stains yellow when cut or bruised, and fresh fruitbodies have an aromatic odor of almond.
Agaricus augustus is part of the Burke Museum's Mushroom of the Month series.
Photo by J. Ammirati