Conocybe filaris Fr. syn. Pholiotina filaris (Fr.) Singer Faden-Samthaubchen Fool's Conecap. Cap 0.5-2.5cm across, conical to convex- umbonate; yellow-brown; glabrous. Gills sinuate-adnate, crowded, broad; pallid to rust-brown. Stem10-40 x 1-1.5mm, equal; yellow to yellow-orange; a distinct, membranous ring on stem apex. Odor not distinctive. Taste not distinctive. Spores smooth, with germ pore at tip, 7.5-13 X 3.5-6.5µ. Deposit cinnamon brown. Habitat in grass or on wood chips. Found throughout most of North America and Europe. Season July-October. Deadly poisonous. Comment This mushroom contains poisons similar to those of the Destroying Angel, Amanita virosa.
Note it has been pointed out to me that the illustrations look very different. The more flat capped specimens were collected in America, but they fit well with the pictures in the Fungi of Switzerland volume 4. The other specimens were checked by Dr Derek Reid at Kew and they fit the description of 'Conecap' very much better. I think it all goes to show that the age of the specimens is very important as they can change quite radically.