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Lichenochora xanthoriae Triebel & Rambold
Family: Phyllachoraceae
Lichenochora xanthoriae image
Robin Schoeninger  
Mycelium: immersed, hyaline, inconspicuous, only at the base of the perithecia, sometimes inducing the formation of small galls on the host thallus; galls: if present, small, concolorous with the host thallus, containing several ascomata Perithecia: completely immersed, only visible by its black protruding ostioles, obpyriform, 200-250 x 150200 µm, with many lipid droplets in all parts; wall: brown, 18-30 µm thick, composed of tangentially flattened cells hymenium: hyaline hamathecium: present as paraphyses and periphyses paraphyses: hyaline, 3-8 µm thick, branching, with delicate walls, dissolving in older ascomata periphyses: numerous, mostly unbranched, 2-4 µm thick and 20-35 µm long asci: unitunicate, subcylindrical, 75-85 x 9-15 µm, 8-spored ascospores: mostly uniseriate, hyaline, 1-septate, broadly ellipsoid, with +equal cells, slightly constricted at the septum, with delicate wall and without a distinct perispore, 12-15-17 x 8-9 µm Pycnidia: not observed. Hosts: thallus and apothecial margins of Xanthoria elegans, outside the Sonoran region also on Caloplaca proteus; infested host thalli not changed in color; commensalic World distribution: a rare species, so far recorded only from a few localities in Europe (Austria, Spain), New Zealand and North America (U.S.A.) Sonoran distribution: Arizona. Notes: The reports on the biological behaviour of Lichenochora xanthoriae are contradictory. Whereas Triebel et al. (1991) indicate on the type specimen originating from Utah the presence of galls containing densely aggregated perithecia, Navarro-Rosin's and Roux (1997) could not find any morphological alterations of European specimens and found the perithecia dispersed. Also a further specimen from Arizona studied by the authors lacks galls and the perithecia are dispersed on the inhabited Xanthoria elegans thallus. Further studies are necessary to show if either L. xanthoriae in this respect is a polymorphic species LICHENOCHORA