Discina ancilis or White saddle

Fruit body cup-shaped or shield-shaped, 5-15 cm across, with a concave upper surface and an uneven, wavy margin. In old specimens it flattens out. Color of the top: reddish-brown, chocolate-brown to olive-brown, surface smooth, sometimes with fine radial veins. The underside (outer surface) is paler, cream-gray, with a fine down.

Cap 2-4 cm, irregularly saddle-shaped, with 2-4 lobes that look like crumpled fabric. Color white or creamy white, with a yellowish tinge in wet weather. Surface smooth on the outside (where the hymenium is), finely warty underneath. Partly fused to the stem at the top. Margins contorted, uneven.

The hymenophore is the upper concave surface of the fruit body (as in all cup fungi — the Pezizales). Smooth, without gills or tubes. Color reddish-brown to brown. Spore print white to pale yellowish.

Smooth hymenium on the upper (outer) surface of the cap lobes. Ascomycete structure — spores form in asci. Spore print white. Spores ellipsoid, smooth, with one large oil droplet.

There is no obvious stem — the fruit body is attached to the substrate at the center by a short (1-2 cm), thick, whitish “holdfast,” often furrowed. It may also be unattached altogether.

Stem up to 10 cm tall, 1-2.5 cm thick, cylindrical, hollow inside. Color white, smooth to the touch, BUT with prominent lengthwise ribs (grooves) running its whole length. This is the key feature — a ribbed white stem.

flesh is thin, brittle, waxy, whitish to yellowish. Does not change color when cut. Fresh, it is toxic — boiling is mandatory.

The flesh is thin, waxy and brittle, white. Doesn't change color when cut. Fragile texture — the mushroom easily falls apart if handled carelessly.

Faint mushroomy smell, nothing distinctive. When fresh, do not taste it.

Faint, nondescript mushroomy smell. Don't taste it raw — potentially toxic.