E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) a cup-shaped fruitbody with a gray-brown upper surface, often with an olive tint, 2) finely scurfy exterior lighter in color and sometimes yellowish, 3) whitish flesh that exudes a juice quickly turning yellow, 4) absent stem, 5) growth on soil, and 6) microscopic characters including spores that are coarsely warty to short-ribbed.

Peziza succosa is found at least in BC, WA, OR, and CA, (Larsen), northeastern North America, west to WI, (Phillips), NY to IA and WI (Seaver), Switzerland (Breitenbach), and the United Kingdom (Dennis).

Upper surface:
1.5-6(10)cm, irregularly cup-shaped to saucer-shaped, then expanding; spore-bearing upper surface hazelnut brown to light brown, "smooth and dull, contracted and wrinkled toward the center", (Breitenbach), 2-5cm across, permanently cup-shaped, disc gray-bister with slight olivaceous tint, (Dennis), reaching 3-4cm across, at first hemispheric, expanding to shallowly cup-shaped or more rarely somewhat disc-shaped, "regular in outline or irregularly contorted, the margin even or occasionally more or less lobed"; upper surface concave or occasionally nearly flat, even brown, becoming darker when old, "often with an olivaceous tint apparently from the spores which have dusted out over its surface", (Seaver), upper surface gray-brown with a slight olivaceous tint (Phillips)

Flesh:
"firm, when injured immediately exuding a juice which quickly turns yellow", (test by dabbing broken piece with white paper or handkerchief), (Breitenbach), thin; whitish; yielding copious bright yellow juice, (Dennis), thin; whitish, yielding yellow juice that makes yellow stains on the edges of the cup and flesh, (Phillips)

Underside:
lighter in color than upper surface, sometimes rather yellowish toward margin; finely brownish-furfuraceous, (Breitenbach), gray, sometimes yellowish at margin, (Dennis), "whitish or yellowish with a slight shade of olive", (Seaver), whitish, grayish, or yellowish, (Phillips)

Stem:
none (Breitenbach, Seaver)

Microscopic:
spores 17-21 x 9.5-11.5 microns, elliptic, coarsely warty to short-ribbed, colorless, with two droplets; asci 8-spored, 330 x 15 microns, positive reaction to iodine; paraphyses cylindric, septate, tips with slightly clavate widenings to 9 microns, sometimes forked, (Breitenbach), spores 17-22 x 9-12 microns, with coarse warts and short ridges, with 2 large oil droplets; asci about 350 x 18 microns; paraphyses straight, colorless, slightly clavate, (Dennis), spores 16-20 x 8-12 microns, elliptic, finally becoming sculptured with rather conspicuous warts 1-2 microns wide, colorless or very faintly yellowish (olivaceous in mass), usually containing 2 distinct oil droplets, obliquely uniseriate; asci 8-spored, reaching a length of 200-225 microns and a width of 12-15 microns, cylindric or subcylindric; paraphyses slender, septate, widened in upper part, "filled with yellowish coloring matter", (Seaver)