About Agaricus moelleri Wasser
This species has the scientific name Agaricus moelleri Wasser. Its cap is off-white, with a greyish-brown patch at the centre and cold grey-brown scaling across the surrounding area. The cap measures 5 to 9 centimetres (2 to 3+1⁄2 inches) in diameter, turns yellow when bruised, is ovate when young, and flattens as it matures. The stem bears a drooping ring, stains yellow very easily when bruised, and this yellow colour changes to brown over time. The flesh of the stem only bruises faintly yellow, with this discoloration most noticeable at the stem base. Like other typical Agaricus species, the gills are crowded and free. They are pink on young specimens, turning brown to black on older fruit bodies. The flesh is white and does not change colour when cut. The odour can resemble ink, iodoform, phenol, sweat, or mouldy straw. The elliptical spores measure 4–6 x 3–4 μm. Agaricus moelleri is found in temperate zones of the Northern Hemisphere, including parts of North America, Europe (including Britain), and Asia. It grows in mixed forests and woods. It is widespread but can be locally rare, and prefers rich alkaline woodland or parkland. Like the yellow stainer (Agaricus xanthodermus), Agaricus moelleri can cause gastrointestinal symptoms in some people but not others when ingested, and is considered toxic.
