Porina microtriseptata Weerakoon & Aptroot, 2016

Weerakoon, Gothamie & Aptroot, André, 2016, Nine new lichen species and 64 new records from Sri Lanka, Phytotaxa 280 (2), pp. 152-162 : 156-157

Porina microtriseptata Weerakoon & Aptroot , sp. nov. ( Fig. 2A–B )

Mycobank No.: MB 817612

Porina with shiny, olive green thallus; ascomata hemispherical, c. 0.2 mm diam., fully covered by thallus except for a brown c. 0.1 mm wide ostiole; ascospores consistently 3-septate, hyaline, fusiform, pointed, 25–27.5 × 2.5–3.5 μm, in two bundles in the ascus. Type: — SRI LANKA. Sinharaja , on bark of tree, 17 February 2015, G.Weerakoon & P.Wolseley Si 129 (holotype PD, isotype F) .

Thallus corticate, smooth, shiny, continuous, covering areas of up to 2 cm diam., thin, olive green, surrounded and partly dissected by a thin black prothallus. Isidia absent. Algae trentepohlioid. Ascomata hemispherical, c. 0.2 mm diam., fully covered by thallus except for a brown c. 0.1 mm wide ostiole. Ascospores consistently 3-septate, hyaline, fusiform, pointed, 25–27.5 × 2.5–3.5 μm, in two bundles in the ascus, surrounded by a c. 1.5 μm wide gelatinous sheath. Pycnidia not observed. Chemistry. Thallus UV–, C–, K–, KC–, Pd–. TLC: No substances detected.

Distribution and habitat: —On tree in wet lowland tropical rain forest. Only known from Sri Lanka.

Discussion: —This species belongs to Porina s.str.. In this group, few species have 3-septate ascospores. The new species is closest to the Australian Porina bacillifera Müll. Arg. ( Müller 1882: 517; McCarthy 2001:), but it is smaller in all dimensions except the ascospores. It differs from P. melanops Malme (1929: 25) by the paler ostiole (black in P. melanops ) and the ascospores that are in two bundles (irregularly distichous in P. melanops ).

Figures

FIGURE 2. A–B, Porina microtriseptata, A, habitus, B, ascospores; C–D, Porina monilisidiata, C, habitus, D, ascospores; E–G, Psoroglaena spinosa, E, habitus, F–G, detail; H–J, Pyrenula multicolorata, H, habitus with sectioned ascoma, I, hamathecium, J, ascospores; K–N, Schistophoron muriforme, K, habitus, L, section through ascoma showing mazaedium, M–N, ascospores. Scale: A, D, H = 0.5 mm, B, M, N = 20 μm, E, K, L = 0.25 mm, F–G = 50 μm, I–J = 25 μm.