Megalotremis cylindrica 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 : 155

Megalotremis cylindrica Weerakoon & Aptroot , sp. nov. ( Fig. 1H–I )

Mycobank No.: MB 817611

Megalotremis with olive grey thallus; ascomata not observed; pycnidia abundant, cylindrical with a widened base, pointed, curved to one side, c. 0.1 mm thick, c. 0.2–0.4 mm high, base covered by thallus, remainder pale citrine yellow; conidia hyaline, ellipsoid, 5.5–7 × 3–3.5 μm, with rather pointed ends.

Type: — SRI LANKA. Sinharaja, on bark of tree, 14 February 2015, G.Weerakoon & P.Wolseley Si114 (holotype PD, isotype F).

Thallus corticate, smooth to granular, dull, continuous, thin, olive grey, not surrounded by prothallus. Algae trentepohlioid. Ascomata not observed. Pycnidia abundant, cylindrical with a widened base, pointed, curved to one side, c. 0.1 mm thick, c. 0.2–0.4 mm high, base covered by thallus, remainder pale citrine yellow. Conidia hyaline, ellipsoid, 5.5–7 × 3–3.5 μm, with rather pointed ends. 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 only known from its pycnidia, but these are so characteristic that it can be described as a new species and assigned to the genus Megalotremis , from which a few more species are known without ascomata. It is closest to the neotropical M. flavovulcanus (Komposch) Aptroot in Aptroot et al. (2008: 69), which has a similar colour of the pycnidium ostiole, but the pycnidia are conical rather than cylindrical.

Figures

FIGURE 1. A–B, Astrothelium conjugatum, A, habitus, B, ascospores; C–E, Heterodermia fragmentata, C, apothecium, D–E, thallus; F–G, Lecanactis minutissima, F, apothecia, G, ascospores; H–I, Megalotremis cylindrica, H, conidiomata, I, conidia and conidiophores. Scale:A, H = 0.5 mm, B = 25 μm, C = 2 mm, D–E = 1 mm; F = 0.2 mm, G = 20 μm, I = 10 μm.