Bolbitius vitellinus (Pers. ex Fr.) Fr. Goldmistpilz Bolbitius jaune d'oeuf Yellow Fieldcap Cap 1–4cm across, acorn-shaped then bell-shaped, finally expanding to almost flat, very thin and almost transparent, chrome yellow at first fading to grey-brown at the margin, somewhat viscid when young drying shiny with age, deeply grooved at the margin. Stem 30–100´2–4mm, very delicate, whitish-yellow with a fine mealy powdering, base downy. Flesh thin and membranous above the gills, stem hollow. Gills crowded, pale yellow at first, later cinnamon or rusty. Spore print rust brown. Spores smooth, elliptic, 11–15 x 6–9µ. Habitat on rotting straw, manured grassland or wood chips. Season summer to late autumn. Frequent. Not edible. Distribution, America and Europe. Note There is a possibility that this well known fungus may have to change name to B. titubans in the future.