Trapelia coarctata
≡Lichen coarctatus Turner ex Sm. in J.E. Smith & J. Sowerby, Engl. Bot. 8: tab. 554 (1799).
=Lecidea coarctata var. exposita Nyl., Bot. J. Linn. Soc. 9: 254 (1866).
≡Lecanora coarctata var. exposita (Nyl.) Nyl., Lich. Nov. Zeal.: 66 (1888).
Lecidea coarctata var. exposita. Holotype: New Zealand. Otago, "near Dunedin, on tertiary quartzose grits, Octob.[er] 1861, Dr Lauder Lindsay" – H-NYL 25884 [specimen annotated by Nylander with a drawing of ellipsoidal, simple spores "0.018–21, 0.008" (Dr O. Vitikainen, pers. comm.)] Isotypes – BM, E.
Description : Flora (1985: 584).
Chemistry : Thallus K−, C+ red, KC−, Pd−; containing gyrophoric acid.
N: Northland (Three Kings Is, Little Barrier I.), Auckland (Waitakere coast), South Auckland (Motuhora I.), Wellington, S: Marlborough (Ship Cove), Canterbury (Hawdon River), Otago (Old Man Ra., Lake Onslow, Mt Teviot, Moa Flat, Rock & Pillar Ra., Leith Valley, Mt Cargill, "Green Island Bluff" [= Black Head, W. L. Lindsay, x.1861, BM, E]), Southland (Lake Monowai, Blackmount near Clifden). St: (Deceit Peaks). On rocks and soil, coastal and inland, on exposed soil in eroded tussock grassland, and on depleted grassland soils associating with Cladia aggregata, Diploschistes muscorum ssp. bartlettii, Endocarpon pusillum, Siphula coriacea, Xanthoparmelia semiviridis; often on recently exposed roadside cuttings or slips, commonly associating with sorediate species of Placopsis. Known also from Great Britain, Europe, Scandinavia, Morocco, Turkey, North America, Venezuela, Brazil, Chile, India, Japan, Indonesia, Marion I., South Georgia, South Shetland Is, and Australia (Hertel 1970a, 1971a, 1977a, 1984b, 2001a; Purvis et al. 1992; Aptroot & van der Knapp 1993; Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Egea 1996; Filson 1996; John 1996; Kondratyuk et al. 1996a; Thomson 1997; Diederich & Sérusiaux 2000; Scholz 2000; Brodo et al. 2001; Llimona & Hladun 2001; Øvstedal & Lewis Smith 2001; Aptroot 2002e; Coppins 2002b; McCarthy 2003c; Nimis & Martellos 2003; Lumbsch & Kainz 2004; Santesson et al. 2004; Elvebakk & Bjerke 2006).
Cosmopolitan
Exsiccati : Hertel (1987a: No. 179).
Illustrations : Hertel (1970a: 172, fig. 1; 177, fig. 8); Rambold & Triebel (1990: 382, fig. 3H); Wirth (1995b: 919); Eldridge & Tozer (1997: 37, fig. 4.15); Dobson (2000: 382).
Trapelia coarctata is characterised by: the smooth, uniform, to minutely areolate, pale-greenish to brownish thallus; the small, scattered, pale red-brown, epruinose, subinnate to emergent, sessile apothecia, with an adhering pseudothalline margin derived from its eruption through the thallus; and ellipsoidal ascospores, 14–17(–21) × 7–10 μm. The lichenicolous fungus * Sphaeria sociella Nyl. [Lich. Nov. Zel. : 66 (1888). Holotype: New Zealand. Sine loco, Charles Knight – H-NYL 25895 (Triebel 1989: 223)] was described as a parasite of T. coarctata. It has scattered, globose to pyriform, black perithecia, 100–200 μm diam.; 4-spored asci; and colourless, thin-walled, 1–3-septate ascospores, 10–12(–15) × 3–4 μm.
