Agaricus urinascens (F.H. Møller & Jul. Schäff.) Singer syn. A. macrosporus (F.H. Møller & Jul. Schäff.) Pilát (illustrated 35% life size) Cap 8–30cm across, convex, margin becoming toothed with age; whitish, splitting into large ochraceous scales or patches. Stem 50–100×25–35mm, often with a fusiform rooting base; whitish-cream, covered in easily removable floccules; ring thick, scaly on the underside. Flesh whitish, sometimes reddening in stem on cutting; firm; taste mushroomy, smell faint, of crushed almonds when young, rapidly more ammoniacal. Gills free; whitish-grey at first, finally dark brown. Spores 8–12×5.5–6.5¼, elliptical. Spore print brown. Cheilocystidia numerous, 8–31×6–16¼, ovate. Habitat in rings in pasture; summer to autumn. Occasional. Edible good. Note the name A. macrosporus was illegitimate.
