onion-stalk parasol

Leucocoprinus cepistipes is a small dapperling mushroom with white flesh. Cap: 3–9 cm. Bulbous when immature becoming convex with a pronounced umbo which may be darker in the centre against the white colour of the rest of the cap. Stem: 6–9 cm in height. 4-10mm thick. Slightly bulbous at the base with a stem ring which may quickly disappear. May discolour slightly yellow or pinkish brown. Gills: White, sometimes discolouring to pinkish brown with age. Free and crowded. Spore print: White. Spores: Ellipsoid and smooth with a tiny pore. Dextrinoid.7–11 x 4–7 μm. Smell: Indistinct. Cap: 3–6.5 cm wide when expanded. Starts paraboloid before expanding to campanulate and then flattening. When immature the surface is brown with brown scales more densely clustered towards the centre but as it expands the surface becomes white or creamy coloured with the brown colour only remaining at the centre. There is yellow bruising when touched and sulcate striations are present at the margins. Stem: 3–13 cm long and 2.5-5mm thick becoming wider at the base and tapering upwards with a hollow interior. The surface has a dense, fine pubescent coating all over and is white when immature becoming cream to brownish-cream coloured with age. It bruises yellow when young and yellow-brown to brown when the mature stem is damaged. Clear drops are exuded when immature and may coat the surface. …

This species has commonly been described from greenhouses and hothouses and is especially noted for growing in bark beds. In 1867 the Belgian botanist Jean Kickx documented Agaricus cepaestipes growing in tanbark in the greenhouses of the Ghent Botanical garden during the summer.

The species is edible, but not very palatable and may be easily confused for toxic species.

The specific epithet cepistipes (originally cepaestipes) is derived from the Latin cepae meaning onions whilst stipes means stalk or stem so 'onion stem'. This is a reference to the bulbous base of Leucocoprinus species which may look reminiscent to the bulb of a small onion.