Schistophoron muriforme 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 : 158

Schistophoron muriforme Weerakoon & Aptroot , sp. nov. ( Fig. 2K–N )

Mycobank No.: MB 817616

Schistophoron with thallus pale yellowish white, surrounded by a usually diffuse brown prothallus; Ascomata sessile , lirelliform or ellipsoidal or branched, c. 0.3–0.5 mm wide, c. 0.3–0.4 mm high, c. 0.7–1.5 mm long, area above hamathecium completely filled with mazaedium, ascospores brown, muriform, 3–7 × 2–4-septate, globose to ellipsoid, 15–30 × 15–18 μm.

Type: — SRI LANKA. Morningside, on bark of tree, 24 April 2015, G.Weerakoon Mo12A (holotype PD, isotype F).

Thallus crustose, continuous, not corticate, dull, pale yellowish white, surrounded by a usually diffuse brown prothallus. Algae trentepohlioid. Ascomata sessile , lirelliform or ellipsoidal or branched, c. 0.3–0.5 mm wide, c. 0.3–0.4 mm high, c. 0.7–1.5 mm long, margin white, c. 0.2 mm wide. Excipulum pale brown. Hypothecium hyaline. Hamathecium not inspersed, hyaline, paraphysoids 2–2.5 μm wide, area above hamathecium completely filled with mazaedium. Ascospores brown, muriform, 3–7 × 2–4-septate, globose to ellipsoid, 15–30 × 15–18 μm, lumina rounded. Pycnidia not observed. Chemistry. Thallus UV–, C–, K–, KC–, Pd+ yellow. TLC: Psoromic acid.

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

Discussion: —Only three other species are known in the genus Schistophoron ( Tibell 1996, Aptroot & Sipman 2007), and none have muriform ascospores, although S. tenue Stirton (1876: 165) has submuriform, 2–3 × 0–1-septate, ascospores.

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.