Pyrgidium montellicum (Beltr.) Tibell, Lichenologist 14(3): 239 (1982) (Fig. 4)

MycoBank number: MB 110065; Index Fungorum number: IF 110065; Facesoffungi number: FoF 10277;

Saprobic on bark. Thallus crustose, farinose, whitish. Prothallus absent. Photobiont absent. Sexual morph: Ascomata apothecial, 190–220 μm diam., 170–190(-210–290) μm high, not stalked, mazaedioid, disc black, sessile, scattered, almost spherical. Excipulum 15(-20)–45 μm thick, brown to black, prosoplectenchymataous, sometimes comprised sclerotized hyphae, thickened basally and gradually become thinner towards the upper. Mazaedium filling the cavity of the fruit-body and more or less projecting beyond the excipular edge and sometimes filled inside the ascomata. Paraphyses 0.5–1.5 μm thick, septate, branched. Asci 25–40 × 4–6 μm ( = 25 × 7 μm, n = 20), cylindrical, 8-spored, unitunicate, tip blunted, not narrowing towards the apex, tholus lacking, apical apparatus inconspicuous, short to log pedicellate. Ascospores 4–7 × 2.5–4.5 μm ( = 7 × 3.5 μm, n = 40) μm, overlapping uniseriate, ellipsoidal, light brown to brown, 0-1-septate, septum slightly dark brown, sometimes constricted at the septum, sometimes constricted at the septum, gattulates at immature, verrucose, irregular ridges longitudinally arranged (Fig. 6; K–P). Asexual morph: undetermined.

Material examined: Costa Rica, Lief Tibell, (Lief Tibell 8306, Lief Tibell 8232, 1981 (UPS L-008798), 1981 (UPS L-996762)

Figure 4. Pyrgidium montellicum (Lief Tibell 8306, Lief Tibell 8232, 1981 (UPS L-008798), 1981 (UPS L-996762), Non-types). A–F, Ascomata on substrate. G, H Vertical section through Ascoma (in water). I, Vertical section through Ascoma (in 5 % KOH) J Vertical section through Exciple. K Paraphyses. L–N Asci (in water). O–R Asci (in 5% KOH). S1–S3, Ascospores (in water). S4–S8 (in 5% KOH). Scale bars: C, D = 500 μm, G–I = 100 μm, J = 20 μm, K = 5 μm, L–R = 30 μm, S1–S8 = 10 μm.