Oily Waxcap

The basidiocarps are agaricoid, up to 10 cm (4 in) tall, the cap convex at first (never conical), becoming shallowly convex to flat when expanded, up to 7.5 cm (3 in) across. The cap surface is smooth, dry to slightly greasy when damp, bright yellow to orange-yellow becoming duller with age and sometimes developing a greyish sheen. The lamellae (gills) are waxy, yellow-orange to orange, rather widely spaced and broadly attached to the stipe. The stipe (stem) is smooth, cylindrical, often compressed and grooved, and cap-coloured. The spore print is white, the spores (under a microscope) smooth, inamyloid, ellipsoid to oblong, often constricted in the middle, about 7.5 to 9.0 by 4.0 to 5 μm. When fruitbodies are cut or rubbed, they release a distinctive, oily smell, said to resemble that of pentatomid insects.

Similar species. Several other waxcaps are similarly coloured, but the widely spaced, orange gills of H. quieta are distinctive and the oily smell is diagnostic.

The oily waxcap is widespread throughout Europe, where it typically grows in old, unimproved, short-sward grassland (pastures and lawns). Recent research suggests waxcaps are neither mycorrhizal nor saprotrophic but may be associated with mosses.