Lecidea lapicida
≡Lichen lapicida Ach., Lichenogr. suec. prod.: 61 (1799) ["1798"].
=Lecidea dunedina pr.p. Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss Kl. 104: 301 (1941). [Material from Kyeburn (J.S. Thomson T2330 [A43]) cited in the protologue above is referable to L. lapicida. The material from Abbott's Hill also cited under his name is referable to L. plana (q.v.).]
=Lecidea vexillaris Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss Kl. 104: 301 (1941).
Lecidea vexillaris. Holotype: New Zealand. Otago, Flagstaff near Dunedin, on rocks 800 m, J.S. Thomson T 1748 [V 135] – W. Isotypes – BM, CHR 347073.
Description : Thallus spreading in irregular patches, 2–5(–8) cm diam., closely attached, 0.1–0.6 mm thick, cracked to areolate, delimited by a thin, black marginal prothallus to 1.5 mm wide, also visible between areolae of thallus. Areolae irregular to angular, 0.1–0.5(–1.2) mm diam., whitish, creamish or greyish, commonly becoming rusty-oxydated on iron-rich substrata, plane or subconvex, smooth to roughened. Medulla I+ violet. Apothecia scattered, solitary to crowded, immersed at first and then with a distinct, white or greyish, raised–conical margin, becoming sessile (not constricted at base) or remaining subimmersed, (0.2–0.8(–1.4) mm diam.; disc plane to subconcave, black, matt, epruinose or rarely thinly white-pruinose; margins persistent, rather thick, raised above surface of disc, matt or shining, concolorous with disc or paler to greyish or grey-white. Hypothecium pale-brown to brown, 100–250 μm thick, subhymenial layer colourless to pale brownish, 25–55 μm thick. Hymenium 50–70 μm tall, colourless, I+ blue; epithecium brownish green, dark-green to black, 10–15 μm thick. Asci 35–55 × 10–14 μm; tholus (3–)8–14 μm thick. Ascospores ellipsoidal, 9–13.5 × 5–7 μm. Pycnidia immersed. Conidia 12–14(–17) × 1 μm.
Chemistry : Cortex K+ yellow, C−, Pd± yellow-orange; exciple K+ yellow, C−, Pd± yellow-orange; containing stictic acid (major) constictic acid (minor) and other compounds of the stictic acid chemosyndrome.
S: Canterbury (Phipps Peak, Arthur's Pass, Two Thumbs Ra.), Otago (Old Man Ra., Poolburn Reservoir, Rock & Pillar Ra., Kyeburn, Flagstaff). On subalpine to high-alpine rocks, at higher levels associating with Bellemerea subsorediza and Tremolecia atrata. It is a widespread bipolar taxon known also from Europe, Great Britain, Scandinavia, Iceland, Greenland, Svalbard Novaya Zemlya, Cyprus, Siberia, Japan, North America (see map in Hertel 1985b: 324, fig. 7; 2001; Schwab 1986; Hertel & Printzen 2004), Colombia, Chile, Argentina, South Georgia, Marion I., South Orkney Is, South Shetland Is, Antarctic Peninsula, Australia, Tasmania (see map in Hertel 1997: 102, fig. 3). See also Øvstedal & Lewis Smith (2001: 221), Øvstedal & Gremmen (2001: 560) and Søchting et al. (2004).
Cosmopolitan
Illustrations : Foucard (1990: fig. 192); Hansen (1995: 99); Brodo et al. (2001: 393, pl. 441); Pope (2005: 57).
Lecidea lapicida var. lapicida is characterised by: the saxicolous habit; the dingy grey-white, areolate upper surface of the thallus that is often rusty-oxydated; the I+ medulla; a brown hypothecium; and the stictic acid chemosyndrome in the medulla.
