Porina monilisidiata 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 : 157

Porina monilisidiata Weerakoon & Aptroot , sp. nov. ( Fig. 2C–D )

Mycobank No.: MB 817613

Porina with shiny, olive green thallus, isidia numerous, corticate, mostly simple, but some branched, wavy to moniliform, cylindrical, c. 0.005 mm diam. and c. 0.3–0.8 mm high; ascomata low conical, c. 0.7–1.2 mm diam., fully covered by a thin layer of thallus through whichs the dark ascoma appear grey-brown, with a black, 0.1–0.3 mm wide ostiole; ascospores consistently 9-septate, 65–75 × 10–13 μm.

Type: — SRI LANKA. Sinharaja, on bark of tree, 17 February 2015, G.Weerakoon & P.Wolseley Si73B (holotype PD, isotype F).

Thallus corticate, smooth or slightly rugulose, covering araes up to 10 cm diam., shiny, continuous, thin, olive green, surrounded by a thin black prothallus. Isidia numerous, corticate, concolorous with thallus, mostly simple, but some branched, wavy to a bit moniliform, cylindrical, c. 0.05 mm diam. and c. 0.3–0.8 mm high. Algae trentepohlioid. Ascomata low conical, c. 0.7–1.2 mm diam., fully covered by a thin layer of thallus through which the dark ascoma appear grey-brown, with a black, 0.1–0.3 mm wide ostiole. Ascospores consistently 9-septate, 65–75 × 10–13 μm. 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 is characterized by the combination of 9-septate ascospores, low perithecium warts of a colour that is markedly different from the thallus, and coralloid isidia. Isidia occur in about a dozen other species of Porina , if the genus is taken in a wide sense. Harris (1995) and Cáceres et al. (2013) give a comparison of several tropical isidioid species. In most species isidia are regarded as a constant character by most authors, although McCarthy (1993) accepts one species, viz. P. tetracerae (Afz. in Ach). Müll. Arg. ( Müller 1885: 401), which has only “occasionally isidioid outgrowths”. Such material was previously described as Clathroporina isidiifera R.C. Harris (1995: 171) . The new species differs by much longer ascospores that are 9-septate, and by much longer isidia than any of the isidiate species described in Porina s.lat.

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.