Flora of New Zealand Series

≡Stigmatidium graphidioides Cromb., Bot. J. Linn. Soc. 15: 233 (1876).

Foradditi onal synonymy see Coppins & Fryday (2006: 94). 

Description : Thallus effuse, thin (to 100 μm thick, exceptionally to 200 μm thick), ochraceous, continuous to weakly rimose, or exceptionally thicker and partly rimose–areolate with angular areolae, 0.2–0.5 mm diam.; without a prothallus. Apothecia usually lirelliform, 0.25–1.15 × 0.2–0.4 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 0.5–0.3 mm wide, when raised often with a few transverse cracks; disc sunken, usually expanded but sometimes slit-like. Exciple copular, reddish brown, K+ brown-red, N−, 60–195 μm thick at base, 37–74 μm laterally and 60–150 μm apically; the upper part often spreading outwards ("involucrellum"-like) onto the surrounding thallus. Hymenium 75–100 μm tall, colourless, I+ blue; epithecium indistinct or present as a reddish brown layer to 15 μm thick. Hypothecium 25–35 μm thick, pale red-brown. Paraphyses distinctly septate but not moniliform. Asci clavate, 60–75 × 15–25 μm, 8-spored, Trapelia -type. Ascospores ellipsoidal or broadly oval–ellipsoidal, simple, colourless, sometimes with a thin perispore, (10–)12–17 × (5.5–) 7–9 μm. Pycnidia immersed, black, 60–100 μm diam., wall reddish brown. Conidia narrowly bacillar, 6–10(–13) × 0.8 μm.

Chemistry : TLC−, all reactions negative.

S: Otago (Lake Onslow, Mt Cargill). On vertical rock faces (schist, basalt) in alpine areas. Known also from Chile, Argentina (Tierra del Fuego and Staten I.), the Falkland Is, Marion I., Prince Edward Is and Tasmania (Hertel & Rambold 1990; Coppins & Fryday 2006: 96, fig. 2 – for a world distribution of the species).

Austral

Illustration : Coppins & Fryday (2006: 95, fig. 1).

Lithographa graphidioides is characterised by: the saxicolous habit; the thin, ochraceous thallus; lirelliform apothecia; a hymenium that is 75–100 μm tall; non-moniliform paraphyses, and simple, ellipsoidal to oval–ellispoidal ascospores, (10–)12–17 × (5.5–)7–9 μm.