Vinegar cup or Elfin saddle

Fruit body up to 8 cm across, cup- or saucer-shaped, 2-4 cm deep. Outer surface yellowish brown, finely warty; inner surface (where the hymenium lies) smooth, yellowish gray-brown, with a silky sheen. Margins thin, often split in mature cups, with an uneven outline.

Cap 3-5 cm, irregularly saddle-shaped, with 2-4 lobes. Color dark gray, graphite, almost black in old specimens. Surface smooth, with a silky sheen in wet weather. Margins wavy and contorted. Partly fused to the stem at the top.

Smooth hymenium on the inner surface of the cup. Spores mature in asci within the hymenial layer. Spore print whitish to cream, spores elliptical, smooth. Chemically, a typical ascomycete.

Smooth hymenium on the upper (outer) surface of the cap lobes. Ascomycete structure — spores form in asci. Spore print white. Spores ellipsoid, smooth, 17-20 × 10-13 µm.

Stem short, 2-4 cm tall, 1-2 cm thick, with sharply defined lengthwise ribs that run up to the base of the cup and continue onto its outer surface. Color cream or whitish. This is the key diagnostic feature of the species.

Stem up to 6 cm tall, 1-2 cm thick, cylindrical, hollow inside. Color pale gray, darkening toward the base. Surface with prominent lengthwise ribs and distinctive pits (lacunae) — hence the name. The ribbed structure is like that of crispa, but the color is completely different.

The flesh is thin, waxy and brittle, whitish. Doesn't change color when cut. Fragile texture, like in all Helvella.

The flesh is thin, waxy and brittle, grayish white. Doesn't change color when cut. Fragile texture.

No pronounced smell, faintly mushroomy. We don't taste it — the mushroom is potentially toxic when raw.

Faint mushroomy smell, no sharp notes. We don't taste it — potentially toxic.