About Phlegmacium ponderosum (A.H.Sm.) Niskanen & Liimat.
Phlegmacium ponderosum is one of the largest species in the mushroom family Cortinariaceae. Its cap is convex when young, growing to 10–30 cm (4–12 in) across and flattening out as it ages. The cap often carries an olive metallic tinge, has a viscid surface, and is frequently marked with small rusty brown scales. The cap margin is ocher in color and stays inrolled until the mushroom reaches full maturity. The mushroom's flesh is yellow-white, thick and firm, and has an odor that ranges from mild to sour. Its gills are rusty brown, adnate, and slightly decurrent. The stalk measures 8–20 cm (3–8 in) in length, 4–10 cm in width, is bulbous at the base, and bears a slimy yellow universal veil; the cortina leaves a rusty brown hairy patch on the upper section of the stalk. The spores of this species are brown and elliptical. The edibility of Phlegmacium ponderosum is unknown, and consumption is not recommended because the species closely resembles deadly poisonous mushrooms. For habitat and distribution, A.H.Sm. recorded specimens growing under Pinus ponderosa and Quercus (oak) species near Cave City, Oregon, and under spruce trees near Crescent City, California.
