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 Add this item to the list   807500 Original description
   
Remarks (public):This is a rather unique species, both in terms of morphology and substrate ecology. At first glance it resembles a species of Ocellularia. However, few species in Ocellularia have small, (sub-)muriform ascospores becoming brown, the most similar being O. albomaculata Hale (Hale 1981): 300). That species is corticolous and its columella does not become irregular. Also, the ascospores are longer and narrower. Very similar in ascoma morphology is O. wandoorensis Nagarkar, Sethy & Patw. (Nagarkar et al. 1986): 78), which, however, differs in having smaller, transversely septate and hyaline ascospores. Surprisingly, molecular sequence data place the new species in the genus Rhabdodiscus (...), where it is ecologically and morphologically quite unique (Rivas Plata et al. 2012). 
Description type:Original description 
Description:Thallus saxicolous, up to 5 cm diam., continuous; surface cracked, light yellowish brown; prothallus absent. Thallus in section 100–150 µm thick, with dense, paraplectenchymatous cortex, 20–30 µm thick, photobiont layer 40–60 µm thick, and medulla 50–70 µm thick, strongly encrusted with clusters of calcium oxalate crystals and small, grey crystals. Photobiont Trentepohlia; cells rounded to irregular in outline, in irregular groups, yellowish green, 8–12  6–10 µm. Ascomata rounded, erumpent to prominent, with nearly complete thalline margin, solitary or often aggregated in pseudostromatic thallus warts, 0.6–1 mm diam., 0.3–0.4 mm high, pseudostromatic warts up to 2 mm diam.; disc covered by 0.1–0.3 mm wide pore filled with white-tipped, often irregular columella usually connected laterally to the excipulum; proper margin distinct, forming a broad brownish rim around the pore; thalline margin smooth, light yellowish brown. Excipulum very dark brown to carbonized, 80–120 µm thick; laterally covered by algiferous thallus, 100–150 µm thick; columella present, broad-stump-shaped to irregular, very dark brown to carbonized, 300–400 µm broad and up to 200 µm high; hypothecium prosoplectenchymatous, 15–25 µm high, pale brownish; hymenium 120–130 µm high, colorless, clear; epihymenium indistinct, 10–20 µm high, colorless. Paraphyses unbranched, apically smooth; periphysoids absent; asci cylindrical, 110–120  15–20 µm. Ascospores 8 per ascus, uniseriate, broadly ellipsoid to oval, muriform with 3 transverse and 1–2 longitudinal septa per segment, 17–25  12–15 µm, 1.3–1.7 times as long as wide, for a long time hyaline but eventually becoming pale brown, distoseptate with lens-shaped lumina, I+ violet-blue when hyaline. Secondary chemistry:—No substances detected by TLC. Distribution and ecology:—This new species is so far only known from the type collection in the northern part of Grande Terre, where it occurs in a relict montane forest. 
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