Leratiomyces riparius

Leratiomyces riparius

Pileus
Cap 2.0-6.0 cm broad, convex at first, the margin often hung with veil fragments, becoming broadly convex, nearly plane with a low umbo in age; surface lubricous when moist, otherwise dry, cream to cream-buff, the disk slightly darker, smooth to innately fibrillose, often with a scattering of appressed, small ochraceous-brown scales; flesh thick at the disk, thin at the margin, white to cream, unchanging; odor and taste mild.

Lamellae
Gills adnate to subdecurrent, moderately broad, close, pallid becoming medium purple-grey, mottled in age.

Stipe
Stipe 5-13 cm broad, 0.3-0.8 cm thick, slender, spindly, often twisted, solid at first but with a thin, hollow core at maturity; equal to slightly enlarged at the base, the latter with stiff buff-colored hairs; surface dry, concolorous with the cap, faintly longitudinally striate at the apex, satiny below or with sparse brown fibrils; flesh cream, unchanging; veil pallid, fibrillose-membranous forming an evanescent superior, torn annulus or leaving fragments on the young cap, becoming purple from adhering spores.

Spores
Spores 12-15 x 6-7.5 µm, elliptical smooth, with a faint apical pore; spore print purple brown.

Leratiomyces riparius is recognized by a cream-buff cap, decorated with veil fragments when young, and a slender, typically twisted stipe. A larger, more robust cousin is Stropharia ambigua. Although similarly colored, its cap is more conspicuously appendiculate, and it fruits in natural woodlands as opposed to grassy areas and woodchips.