Five new species of Graphidaceae (Ascomycota, Ostropales) from Thailand Author Naksuwankul, Khwanyuruan Author Kraichak, Ekaphan Author Parnmen, Sittiporn Author Luecking, Robert Author Lumbsch, H. Thorsten text MycoKeys 2016 17 47 63 http://dx.doi.org/10.3897/mycokeys.17.10512 journal article http://dx.doi.org/10.3897/mycokeys.17.10512 1314-4049-17-47 Ocellularia thailandica Naksuwankul, Kraichak & Lumbsch sp. nov. Figure 4 F-H Type. THAILAND, Ubon Ratchathani Province, Pha Tam National Park, trail to Huai Sanom, 15°27'N , 105°34'E , 245 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8458 (holotype: MSUT; isotype: F). Diagnosis. Differing from the similar Ocellularia viridipallens in having broader ascospores with up to 7 septa. Etymology. The specific epithet refers to the country where the type specimen was collected. Description. Thallus corticolous, epiperidermal, up to c. 5 cm diam., continuous; surface uneven-verrucose to rimose, light yellowish green, medulla white; prothallus absent. Thallus in section 40-60 µm thick, with prosoplectenchymatous cortex, 5-7 µm thick, photobiont layer 15-25 µm thick, and medulla 20-30 µm thick, with scattered clusters of calcium oxalate crystals. Photobiont Trentepohlia ; cells rounded to irregular in outline, in irregular groups, green, 7-8 x 5-9 µm . Ascomata rounded, erumpent, with complete thalline margin, 0.3-0.5 mm diam., 0.12-0.2 mm high; disc covered by 0.05-0.1 mm wide pore; proper margin indistinct, entire to slightly fissured, visible as whitish rim around the pore; thalline margin entire to slightly fissured, smooth, light yellowish green. Excipulum entire, prosoplectenchymatous, brown to dark brown, 15-20 µm wide, fused with thalline margin and difficult to separate from the bordering periderm; laterally covered by algiferous, corticate thallus containing periderm layers; columella present, finger-like, carbonized, up to 100 µm broad and 120-135 µm high; hypothecium prosoplectenchymatous, 5-10 µm high, hyaline; hymenium 125-140 µm high, hyaline, clear; epithecium indistinct, 5-10 µm high, hyaline. Paraphyses unbranched, apically smooth; periphysoids absent; asci cylindrical to narrowly clavate, 87-100 x 12-15 µm . Ascospores 8 per ascus, ellipsoid, 5-7-septate, 20-23 x 7-8 µm , hyaline, distoseptate with lens-shaped lumina, I+ violet-blue. Pycnidia not seen. Secondary chemistry. No substances detected by TLC. Distribution and ecology. The new species was collected in northeastern Thailand, growing on bark in a dry evergreen forest. It is known only from the type locality. Remarks. This new species is closely related to Ocellularia albocincta (Fig. 2). However, this species differs in lacking a columella ( Papong et al. 2010 ). Morphologically it resembles Ocellularia viridipallens , which differs in having narrower ascospores. The species would key out at alternative 60 in the Ocellularia key for Thailand ( Sutjaritturakan and Kalb 2015 ). Additional specimen examined. THAILAND, Ubon Ratchathani Province, Pha Tam National Park, trail to Huai Sanom, 15°27'N , 105°34'E , 245 m, dry evergreen forest, on bark; 12 April 2013, K. Papong 8439 (MSUT).