Miriquidica effigurata Fryday & Coppins
Lichenologist 40: 284. 2008
Thallus effuse, wide spreading, to 5 cm or more, thick, (0.50.7 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 3070 µm thick, composed of vertically arranged hyphae 34 µm thick, upper 510 µm pale- to mid-brown, cells brown pigmented, epinecral layer of hyaline cells 050 µm. Basal layer 607- µm thick dark red-brown (K+ red-purple). Primary photobiont chlorococcoid, cells 1012(15) µm. Secondary photobiont cephalodia frequent, black, blue-black when wet, rounded to angular, flat to slightly convex, 0.50.8(1.1) µm, between areoles, surface rough, occasionally becoming subfruticose, cyanobacterium ?Scytonema, cells 8.512 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 7090 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 34 µm and brown pigmented but without distinct cap. Hypothecium upper 7080 µm hyaline, lower 100120 µm dark brown (K+ red purple). Asci ?Lecanora-type (I+ tholus, with a feint ocular chamber), broadly cylindrical to subclavate, 5055 × (15)20 µm; ascospores 8/ascus, simple, hyaline, broad ellipsoid (9)1012 × (5)5.56.5(7) µm. Exciple dark brown 2030 µm wide.
Conidiomata: Pycnidia, frequent, often abundant; pale brown, immersed, rounded to linear, 0.050.1 × 0.030.05 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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