Viridothelium virens

Viridothelium virens (Tuck. ex Michener) Lücking, M.P. Nelsen & Aptroot, in Lücking et al., Lichenologist 48(6): 759 (2016).

 ≡ Trypethelium virens Tuck. ex E. Michener, in Darlington, Fl. Cestrica, Edn 3 (Philadelphia): 453 (1853)

           Index Fungorum number: IF 816883; Facesoffungi number: FoF 12019 , Fig. 1

Description:

Lichenized on bark. Thallus distinctly corticate with yellow-brown to dark-brown color. Sexual morph: Ascomata 155–385 µm diam., 225–515 µm high, aggregated in pseudostromata, dark brown to black or covered by algal-free, sterile tissue, globose, coriaceous to carbonaceous, ostiolate. Excipulum 22–25 µm prosoplectenchymatous, dark brown to brown-black. Hamathecium 1.2–1.8 µm comprising trabeculate pseudo paraphyses, filiform, hyaline, straight, branched and anastomosing, embedded in a thick, gelatinous matrix. Asci 105–225 × 20–25 µm (x̄ = 167.5 × 24.2 µm, n =10), 8-spored, bitunicate, fissitunicate, obclavate, short pedicellate, with non-amyloid ocular chamber. Ascospores 45–60 × 14–16 µm (x̄ = 53.4 × 14.8 µm, n =10), irregularly arranged to biseriate, fusiform-ellipsoid to oblong-cylindrical, hyaline, multiseptate, with thin distinct distosepta, smooth-walled, not constricted at the septa, sometimes surrounded by an evanescent mucilaginous sheath. Asexual morph: Unknown.

Material examined: The United States, White Mountain, New Hampshire, on unidentified bark, 1848, W. Oakes (M0207157, authentic specimen).

Fig. 1 Trypethelium virens (M0207157, authentic specimen). a–c Herbarium material. d Section through ascomata. e Peridium. f Trabeculate pseudo paraphyses. g Ostiole. h Prosoplectenchymatous excipulum. i–n Asci. o–t Ascospores. Scale bars: c = 5000 μm, d = 100 μm, e, g, h = 20 μm, f = 5 μm, i–n = 50 μm, o–t = 30 μm.