Description
Thallus effuse, ochraceous, thin, continuous to weakly rimose, or exceptionally thicker and partly rimose-areolate with angular areoles c. 0.20.5 mm wide; prothallus not evident. In section to 100 m thick, exceptionally to 200 m; ecorticate, but with 512 m tall epinecral layer; medulla containing many mineral fragments; I+ weakly blue, but reaction often patchy or obscured by mineral fragments. Photobiont cells 58 m diam. or ellipsoid and to 9 7 m. Apothecia usually lirelliform, 0.251.15 0.20.4 mm, straight to curved, simple or with 1(4) branches, but occasionally rounded and Rimularia-like, sometimes even with a central umbo; black, usually becoming emergent and with raised margins and obtuse apices, sometimes a few lirellae are more innate with a slit-like disc, a seemingly narrower margin and acute apices; margin 0.070.3 mm wide, when raised often with a few transverse cracks; disc sunken, usually expanded but sometimes slit-like. Exciple cupulate, reddish brown, K+ brown-red pigment going into solution, N, 60195 m thick at base, 3774 m laterally and 60147 m at the apex; the upper part often spreading outwards (involucrellum-like) onto the surrounding thallus (or adhering portion of thallus). Hymenium c. 75100 m tall, hyaline, I+ blue; epithecium indistinct or present as a reddish brown layer c. 15 m tall. Hypothecium 2634 m tall, dilute red-brown. Paraphyses distinctly septate but not moniliform, 1.7 2 m wide, not swollen at apices, but apices sometimes surrounded by a brown-pigmented hood 33.5 m wide. Asci clavate, 6275 1724.5 m, 8-spored; in K/I with amyloid outer wall, and tholus with a thin amyloid apical cap and amyloid flanks (Trapelia-type). Ascospores (10)1217 (5.5)79 m, ellipsoid or broadly ovoid-ellipsoid, simple, hyaline, sometimes with a thin perispore.
Pycnidia usually present but rarely abundant, immersed, black, 60100 m diam.; wall reddish brown. Conidia narrowly bacilliform, 611(13) c. 0.8 m.

Chemistry. Thallus K, C, KC, P, UV; no substances detected by TLC.

Ecology and distribution. On siliceous rocks and stones, at altitudes from near sea-level to 1320 m. Lithographa graphidioides is a widely occurring species in the southern subpolar region at latitudes 42S to 5451S, being particulalry frequent in southern South Americ. It is known from Tasmania (Hertel & Rambold 1990) and has recently been reported from South Island, New Zealand (Galloway 2007), but is apparently absent from the Auckland Islands and Campbell Island.

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Thallus


Apothecia


Apothecia


Distribution