Strigula minutula
Description : Thallus corticolous, determinate, continuous to sparingly rimose, pale-green to dark grey-green, slightly darker at margins, smooth, somewhat glossy, ecorticate, (25–)40(–60) μm thick. Photobiont Trentepohlia, cells broadly ellipsoidal to subglobose, 5–10(–14) × 5–8 μm. Hyphae 2–3 μm diam. Prothallus not apparent. Perithecia very numerous, prominent, but partly or almost entirely overgrown by a thick thalline layer, (10–)15–25(–30) μm, normally solitary, hemispherical, subglobose or subconical. Ostiole inconspicuous. Involucrellum brown-black extending to exciple base level, (0.15–)0.2(–0.28) mm diam., 20–30(–40) μm thick. Centrum broadly ovate to subglobose, 0.08–0.17 mm diam. Exciple medium- to dark-brown, 10–15 μm thick. Paraphyses simple to sparingly branched, c. 1 μm thick. Periphyses absent. Asci fissitunicate, 8-spored, elongate-cylindrical, 45–60 × 6–8 μm. Ascospores hyaline, elongate-ellipsoidal to elongate-fusiform, 1-septate, uniseriate in ascus, (6–)8(–10) × (2–)2.5(–3.5) μm. Pycnidia 80–130 μm diam., black above, pale- to dark-brown below, with a simple conidiogenous layer of hyphae 12–20 × 1 μm. Macroconidia 1-septate, elongate-ellipsoidal to cylindrical, 4.5–7.5 × 2–2.5 μm, developing obliquely from the tips of short, unbranched conidiogenous hyphae, with variously developed, apical gelatinous appendages. Microconidia not seen.
S: Nelson (Hackett River). On bark of Podocarpus totara. Known also from Queensland, Australia, where it occurs on deeply shaded aquatic and semi-aquatic rocks (McCarthy 1995e).
Australasian
Illustration : McCarthy (1995e: 328, fig. 3).
Strigula minutula is characterised by: the comparatively dark thallus; the very small perithecia that are at least partially covered by a thalline layer; and the extremely small, 1-septate ascospores.
