Trapelia macrospora Fryday
Biblioth. Lichenol. 88: 144. 2004.

Thallus widespreading, 5-10 cm across, or in smaller patches, thin, c. 0.1 mm thick, creamy-grey, cracked-areolate. Photobiont chloroccocoid, cells globose, 8-10 m diam., (?Chlorella).
Apothecia dark brown-black, reddish brown when wet, lecideine, orbicular, (0.4-)0.7-0.9(-1.2) mm diam., immersed in the thallus with a white, raised pseudothalline margin 0.08-0.12 mm wide, separated from the thallus by a thin fissure; disc shallowly concave without a visible proper margin. Exciple thin, pale brown. Hypothecium orange-brown, 150-180 m, mostly composed of vertically arranged hyphae. Hymenium hyaline, 150-180 m thick, I+ blue; epihymenial zone dilute orange-brown, 50-60 m thick. Paraphyses very slender, 1.5-2.0 m wide, richly branched and anastomosing, scarcely swollen at the apices, without a pigmented cap. Asci cylindrical to slightly clavate, 85-100 x 30-35 m, Trapelia-type. Ascospores hyaline, simple, broadly-ellipsoid (25-)27-30 x (12-)15-18(-19) m.
Conidiomata not observed.

Chemistry: K, C+ red, Pd. Gyrophoric acid detected by TLC.

Notes: Originally known only from Campbell Island, but recently reported from Tasmania (G. Kantvilas pers. comm.)

Notes: This species is, in some ways, similar to the cosmopolitan Trapelia coarctata (Sm.) M. Choisy. However, it is readily separated from this species by its innate apothecia, its larger, more broadly ellipsoid ascospores (15-25 x 7-13 m in T. coarctata), and broader epihymenial zone. The large ascospores also serve to separate it from all other species of Trapelia.
Associated lichens include Lecidea lygomma, Placopsis sp., Psoroma sp., and Stereocaulon sp.

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Thallus and apothecia