Coenogonium zonatum
≡Biatorinopsis zonata Müll.Arg., Lich. Epiphylli Novi: 16 (1890).
≡Dimerella zonata (Müll.Arg.) R.Sant., Symb. Bot. Upsal. 12 (1): 399 (1952).
Description : Thallus usually 10–20(–30) mm diam. rarely to 60 mm, smooth, greyish green, usually but shining at margins, 20–25 μm thick. Prothallus thin, well developed, white, 0.1–0.3(–0.5) mm wide. Apothecia strongly constricted at base, 0.25–0.5 mm diam., disc plane, pale reddish yellow, epruinose, margin not prominent, distinct, to 0.05 mm thick, pale-yellow to pale yellow-red, smooth or slightly uneven. Exciple paraplectenchymatous, colourless, 30–70 μm thick in lateral parts, to 70 μm thick basally. Hymenium hyaline, 45–65 μm tall. Paraphyses c. 1 μm diam., apices swollen to 2–4 μm diam. Asci cylindrical, 40–70 × 4–6 μm, 8-spored. Ascospores uniseriate, fusiform, 6–12 × 2.5–4(–4.5) μm. Pycnidia in pale warts, 0.05 mm diam., rare. Conidia 1-septate, bacillar, 12–16 × 2–3 μm.
N: Northland (Hen Island). On Nestegis apetala leaves in mixed forest (Lumbsch & Hayward 1990), Wellington (Horokiwi Reserve), on leaves of forest trees. Known also from Africa, Mexico, South America and Australia (Santesson 1952; Santesson & Tibell 1988; Filson 1996; McCarthy 2003c, 2006; Herrera-Campos et al. 2004).
Pantropical
Illustrations : Santesson (1952: 400, fig. 72 – as Dimerella zonata); G.C.Hayward & B.W. Hayward (1978: 125, fig. 2A – as Catillaria sp.).
Coenogonium zonatum is characterised by: the foliicolous habit; its relatively large apothecia (0.25–0.5 mm diam.); and the well-developed white prothallus.
