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

Summary:
Features include small cup-shaped to cushion-shaped yellow to green yellow fruitbodies that become dark brown, scurfy exterior and margin that are lighter in color, growth on dung, especially of cow, and microscopic characters including elliptic spores ornamented by 7-9 anastomosing light colored lines. Van Brummelen gives Ascobolus stercorarius (Bull. per St. Amans) Schroet. as a synonym, and the online Species Fungorum, accessed November 3, 2013, gave the latter as the valid name with Ascobolus furfuraceus Pers. as a synonym. On the other hand Dennis says Ascobolus stercorarius (Bull. ex St.-Amans) J. Schroet. emend. Olive may be distinguished from Ascobolus furfuraceus Pers. ex Fr. by the former''s shorter spores 17-22 x 9.5-12.5 microns on which about 5-7 freely anastomosing striae are visible at one time.

Ascobolus stercorarius is found at least in BC, WA, OR, ID, CA, and CO, (Larsen for A. furfuraceus Pers. ex Pers.). Collections of A. furfuraceus Pers. per Hook. were examined from OR, ID, AL, CA, CO, CT, DC, FL, GA, IA, MA, ME, MO, MT, NC, NE, NH, NY, OH, OK, PA, SC, TN, WY, Bermuda, Greenland, Argentina, Chile, Venezuela, Austria, Belgium, Czechoslovakia, Denmark, Finland, France, Germany, Hungary, Iceland, Italy, Monaco, Netherlands, Poland, Portugal, Romania, Sweden, Switzerland, United Kingdom, India, Pakistan, Algeria, Madagascar, and Australia, (Brummelen).

Upper surface:
0.1-0.3(0.5)cm, cup-shaped becoming flat and disc-shaped to slightly cushion-like; sulphur-yellow to green-yellow when young, later increasingly violet-brown to black-brown or olive-brown (because of darkening spores); smooth becoming rougher (because of projecting asci); margin slightly projecting, lighter in color than spore-bearing surface and finely scurfy, (Breitenbach), 0.05-0.5cm across, 0.04-0.08cm high, at first closed and spherical, then opening and hemispheric or cup-shaped, finally saucer-shaped, disc slightly concave or flat; at first yellowish, greenish or yellowish green, dotted with almost black protruding tips of asci, finally often brownish or blackish brown; margin "furfuraceous, denticulated, membranaceous or smooth", (Brummelen)

Underside:
lighter in color than upper surface; finely scurfy, (Breitenbach), yellowish green or yellowish, often becoming olive-green, ochraceous, or brownish; "wholly or partially, coarsely or finely, whitish furfuraceous, almost smooth or smooth", (Brummelen)

Stem:
none (Breitenbach, Brummelen)

Microscopic:
spores 23-26 x 10-14 microns, elliptic, colorless when young and surrounded with a gelatinous sheath, "violet-brown when mature and ornamented with 7-9 anastomosing light-colored longitudinal ribs", asci 8-spored, 200-220 x 20-22 microns, amyloid; paraphyses "slender, septate, with slight clavate thickenings to 8 microns at the tips", (Breitenbach), spores (16)19-28(32) x (9)10-14(16) microns, elliptic, "ornamented with more or less longitudinal, occasionally anastomosing striae, rarely swollen and reticulated, with unilateral mucilaginous substance", at first colorless then violet, finally often purplish brown, when mature biseriate or irregularly disposed; asci 8-spored, (120)180-250 x (20)24-30(32) microns, clavate, walls amyloid, narrowing downward into rather short stem, rounded at top; paraphyses filiform, 2-4 microns thick, "usually scarcely thickened above, only very rarely with ellipsoid, strongly swollen cells up to 21 microns thick", simple or branched, septate, embedded in yellowish or yellowish green mucus, (Brummelen), spores 22-28 x 12-13 microns, elliptic, ornamented with longitudinal occasionally anastomosing lines, about 8 or 9 of which are visible on each view of the spore, spores violet then brown; paraphyses slender, embedded in yellow mucus, (Dennis)