Hygrophorus piceae, commonly known as the white waxy cap, is a species of mushroom in the family Hygrophoraceae. While technically edible, it is considered to be bland and slimy.
The cap of Hygrophorus piceae is white in color and about 1-5 centimeters in diameter. It starts out campanulate to convex and becomes broadly convex or flat in age. It is slimy when wet. The stipe is about 2-7 centimeters long and 3-10 millimeters wide. It is also white in color, but can become yellowish in older specimens. The gills are whitish in color and adnate to decurrent. The spore print is white.
Hygrophorus piceae has at least two extremely similar species that have yet to be described. Other similar species include the larger, slimy-stalked H. eburneus, the almondy-smelling H. sitchensis, and the beige or off-white H. gliocyclus.
Hygrophorus piceae can be found in the Pacific Northwest, where it often grows in spruce forests near the coast. It also sometimes occurs at higher elevations.