Caccobius minusculus
Caccobius minusculus Kimbr
Coprophilous on rather old rabbit dung. Ascomata apothecial, solitary or in small groups, superficial, sessile, 0.12-0.20 mm diam., 0.18-0.25 mm high. Receptacle cylindrical to obconical, sometimes becoming pulvinate, pinkish red; margin not differentiated.Disc flat to convex, roughened by the prominent tips of asci, pinkish red. Hymenium about 150 pm thick. Hypothecium scarcely differentiated. Excipulum not clearly differentiatedin a cortex and a medulla, near the base 50-70 pm thick of isodiametric cells 5-9 pm diam. (textura globulo-angularis), only a single layer ofrows of hyaline oblong cells at the sides, 10-16 x 2.5-5.0 pm (textura porrecta), smooth. Asci broadly cylindrical with a short stalk, rounded above, the ascus wall strongly swelling or even dissolving in 10% NH4OH, (80-) 130-150x 33-36pm, about 1000-spored, with the apex strongly thickened on the inner side (2.5-5.0 pm), not blue with iodine. Ascospores ellipsoid (length-width ratio2.0-2.8, average 2.2), hyaline, (4.5-)5.4-6.0 x 2.3-2.8 pm, withoutoil globules, air bubbles, or granules, smooth. Paraphyses frequent, septate, cylindrical, simple, hyaline to pale pinkish, 1.8-2.5 pm thick, not or slightly enlarged up to 3.5 pm at the tip, not embedded in mucus.
Specimens examined. NORWAY: 0stfold, Hvaler, N. Kirk0y, Utengen, on rabbit dung, 16.XI.1996 and 5.XII.1996, R. Kristiansen A. Sagbakken RK 96.130 (L); id. 18.X.1997, R. Kristiansen RK 97.20 (L). — CANADA: Ontario, Nipissing Distr., South of Whitney, onrabbit dung, 26.IX.1956,R.F. Cain (isotype of Caccobius minusculus Kimbr. in Kimbr. & Korf; TRTC 32390).
Caccobius minusculus. a-c.Habit of fruit-bodies,x 90; d. detail of excipulum seen from outside x 250; e. paraphyses, x 500; f-h. asci, x 500; f,h, in 10% NH4OH, g in water; i. detail of top of dehisced ascus, x 800; j-o. ascospores, x 2700 (all from R. Kristiansen & A. Sagbakken RK 96.130).
References:
Van Brummelen J & Kristiansen R. Two rare coprophilous ascomycetes from Norway. Persoonia 17, 119-125
Recent Genus
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Ionomidotis
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