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Xylopsora friesii (Ach.) Bendiksby & Timdal
Family: Umbilicariaceae
[Biatora friesii (Ach.) Tuck.,  more]
Xylopsora friesii image
Troy McMullin  
Thallus: squamulose squamules: up to 1.0 (-1.5) mm diam., adnate, concave, plane or weakly convex upper surface: grayish green or greenish to dark brown, dull or shiny; margin: entire, crenulate or incised, not upturned, concolorous with upper side; soredia absent upper cortex: up to 50 µm thick, composed of thin-walled hyphae Apothecia: up to 1.0 (-1.4) mm diam., marginal or laminal, plane; disc: black, epruinose, often gyrose; margin: remaining prominent, more or less flexuose; exciple: composed of closely conglutinated hyphae, brown in inner part, brownish black in the rim, not containing crystals, K+ brown, N-; hypothecium: dark brown; epithecium: dark brown, not containing crystals, K+ brown, N-; paraphyses: without swelling or pigment cap in apical cell asci: with a poorly developed tholus containing a small axial body ascospores: broadly to narrowly ellipsoid, simple, 4.5-7.5 x 2.5-3.5 µm Pycnidia: black, sessile, attached laminally or marginally to the squamule or apparently directly to the substrate conidia: narrowly ellipsoid to shortly bacilliform, 2.5-5 x c. 1 µm Spot tests: upper cortex and medulla K-, C-, KC-, P- Secondary metabolite: an unidentified secondary product. Substrate and ecology: on bark and wood of conifers, usually charred, in conifer forests at 1890-2960 m alt. World distribution: Asia, Europe, and North America Sonoran distribution: Arizona, uncommon. Notes: The species has been much confused with H. oligospora in North America, see that species for discussion. The unidentified compound belongs in RF-classes 2-3:3-4:2-3, is UV+ white, and turns orange with H2SO4 and heat.