Miriquidica effigurata Fryday & Coppins
Lichenologist 40: 284. 2008

Thallus effuse, wide spreading, to 5 cm or more, thick, (0.5–0.7 mm thick), deeply cracked-areolate, in places subsquamulose with effiguate margin and dark lower surface, areoles (0.5–)0.8(–1.1) µm, flat, sometimes slightly convex, pale-grey (rarely brown), often with numerous pale brown immersed pycnidia. Upper cortex 30–70 µm thick, composed of vertically arranged hyphae 3–4 µm thick, upper 5–10 µm pale- to mid-brown, cells brown pigmented, epinecral layer of hyaline cells 0–50 µm. Basal layer 60–7- µm thick dark red-brown (K+ red-purple). Primary photobiont chlorococcoid, cells 10–12(–15) µm. Secondary photobiont cephalodia frequent, black, blue-black when wet, rounded to angular, flat to slightly convex, 0.5–0.8(–1.1) µm, between areoles, surface rough, occasionally becoming subfruticose, cyanobacterium ?Scytonema, cells 8.5–12 µm diam.
Apothecia often absent, lecideine, immersed in the thallus, mostly compound, some becoming almost gyrose, occasionally singular and simple; black, disc red-brown when wet, flat with persistent, thin (0.05 mm thick) and barely raised, black margin. Hymenium 70–90 µm high, hyaline, upper 10-15 µm dilute brown, I+ blue, merging below with hyaline hypothecium; paraphyses slender, branched and anastomosing, swollen at apex to 3–4 µm and brown pigmented but without distinct cap. Hypothecium upper 70–80 µm hyaline, lower 100–120 µm dark brown (K+ red purple). Asci ?Lecanora-type (I+ tholus, with a feint ocular chamber), broadly cylindrical to subclavate, 50–55 × (15–)20 µm; ascospores 8/ascus, simple, hyaline, broad ellipsoid (9–)10–12 × (5–)5.5––6.5(–7) µm. Exciple dark brown 20–30 µm wide.
Conidiomata: Pycnidia, frequent, often abundant; pale brown, immersed, rounded to linear, 0.05–0.1 × 0.03–0.05 µm. Conidia filliform, curved, c. 20 µm long.

Chemistry: K–, C–, Pd–, UV–; confluentic acid and accessories by TLC.

Distribution: twelve collections from Campbell island, two from the Auckland Islands.

Notes: The placement in Miriquidica is based on the ascus structure (indistinct Lecanora-type) and general thallus and apothecial morphology. However, both cephalodia and confluentic acid are otherwise unknown in Miriquidica, and so the placement must be considered tentative.

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