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Strigula stigmatella (Ach.) R. C. Harris
Family: Strigulaceae
[Arthopyrenia faginea (Schaer.) Swinscow,  more]
Strigula stigmatella image
Stephen Sharnoff  
Thallus: continuous, effuse, immersed in the substrate upper surface: white to pale gray, smooth algae: trentepohlioid Perithecia: hemispherical, black, semi-immersed in the thallus, 0.3-0.5 mm diam. involucrellum: closely clasping the exciple ascomatal wall: black, absent below the hamathecium true exciple: pale brown to colorless hamathecium: composed of branched pseudoparaphyses, anastomosing above the asci, filaments c. 1 µm wide, not inspersed with oil droplets asci: clavate to cylindrical, 70-80 x 12-15 µm, with 8, irregularly arranged ascospores ascospores: hyaline, fusiform, (4-) 6-7 (9)-septate (starting with a median euseptum), 25-45 x 5-8 µm; walls: not ornamented, without a gelatinous sheath Pycnidia: c. 100 µm diam.; conidia macroconidia: 5-7 septate, 20-30 x 4-6 µm; microconidia: not seen Spot tests: all negative, UV negative. Secondary products: none detected Substrate and ecology: on bark of various woody plants World distribution: temperate regions of the Northern Hemisphere Sonoran distribution: only recorded from southern California.