Search on : Taxa descriptions


 Add this item to the list   818198 Original description
Remarks (public):This new species is closely related to O. albocincta (Fig. 2). However, this species differs in lacking a columella (Papong et al. 2010). Morphologically it resembles O. viridipallens, which differs in having narrower ascospores with up to 5 septa. 
Description type:Original description 
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 35–50 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 × 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 × 12–15 µm. Ascospores 8 per ascus, ellipsoid, 5–7-septate, 20–23 × 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. 
Taxon name: