Description
Thallus delimited, ±placodioid, at least 5 cm (probably 10 cm or more) diam., deeply rimose-areolate with areoles c. 1–4 mm across, ochraceous, ±glossy in younger parts; prothallus not evident. In section: thallus 0.1–1.2 mm thick; cortex 35–75 µm thick, hyaline or upper part dilute straw-brown, hyphae densely compacted, c. 2.5–3 µm wide, cortex ±overlain by a hyaline epinecral layer c. 5 µm thick; algal layer 145–220 µm thick; medulla I–, up to c. 1 mm thick, hyaline, but containing large amounts of mineral particles from the substratum giving an outward, light grey to pale ochraceous appearance. Photobiont cells ±globose, 7–10 µm diam., some seen to be dividing by binary fission.
Apothecia lirelliform in ±stellate clusters c. 1.5–4 mm diam., innate within the areoles, or with the margins raised above the surface level of the thallus; lirellae elongate, serpentine and frequently branched, to 2 mm long and c. 0.1–0.2 mm wide, black; disc slit-like, bordered by a black margin (upper exciple), which is in turn sometimes bordered by a thin white zone of the thallus cortex. In section, lirellae 250–280 µm wide and 250–350 µm tall. Exciple cupulate, dark red-brown, K+ brown-red pigment going into solution, N–, 50–70 µm thick at base, 40–60 µm thick laterally and 80–100 µm thick at the apex [margin, or ‘labium’]. Hymenium 98–147 µm tall, hyaline, without a well-defined epithecium, I+ blue. Hypothecium not well-delimited from the hymenium, c. 50–60 µm tall, hyaline or dilute brown-red. Paraphyses richly branched and anastomosed, distinctly moniliform throughout, c. 2– 3 µm wide. Asci clavate, 85–115 × 20–30 µm, 8-spored; in K/I with an amyloid outer wall, and an apparently non-amyloid tholus [few good preparations obtained]. Ascospores 14–19 × 8–9 µm, ellipsoid, transversely 3-septate, or more usually submuriform with diagonal septa and 3–6 cells in optical section; a c. 1.5 µm thick perispore apparent in some preparations.
Conidiomata not seen.

Chemistry: thallus K–, C–, KC–, P–, UV–; no substances detected by TLC.

Distribution and Ecology: Known only from a single collection on Campbell Island (NZ).

Distribution in Google Earth

Notes: This species and L. skottbergii from South America are the only species in the Trapeliaceae/Xylographaceae with muriform ascospores, and it is probable that a new genus should be erected to accommodate these two species.

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Thallus


Apothecia


Ascus and ascospores