Imbricated or dimidiate. Pilei at first convex and horizontal, then expanded and ascending, flabellate or more or less oyster-shell-shaped, margin often incurved, glabrous, moist, even, but the cuticle sometimes torn into squamules, often almost black when quite young, then brownish-grey, clear blue-grey with a violet tinge, or lavender colour, often becoming yellowish when old; 6-15 cm. across; flesh thick, white, brownish just below the cuticle, up to 2 cm. thick; gills decurrent, anastomosing behind and forming a network down the under-surface of the stem, rather distant, broad, white, or tinged yellow, never pinkish; spores elliptical, white, 10-12 x 4-5 µ; stem obliterated, or short, firm, thickened near the pileus, base downy or strigose.

New Zealand. Australia, Europe, Siberia, South Africa.

On trunks.