Cap, gills below, no stem & usually on wood [stemless mushrooms & the like] species
The fruitbodies of most of the species in this group grow from wood, but sometimes that wood may be buried (e.g. dead roots). Some examples of fruitbody attachment are:
Cap roughly semicircular and attached to wood along the cap’s diameter.
Cap more-or-less circular but tapering to a narrow attachment point.
Cap on the underside of dead wood and attached by its top.
Cap like an upside-down cup, with the edge of the cup attached to wood.