Flora of New Zealand Series

≡Lecidea subcoarctata C.Knight, Trans. N. Z. Inst. 8: 316 (1876).

≡Biatora subcoarctata (C.Knight) Hellb., Bihang K. Svenska Vetensk.-Akad. Handl. 21 (3/13): 106 (1896).

=Lecidea gallinarum Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss Kl. 104: 299 (1841).

=Lecidea allanii Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss. Kl. 104: 306 (1941).

=Lecidea circumdiluens Zahlbr., Denkschr. Akad. Wiss Wien Math.-naturwiss. Kl. 104: 307 (1941).

=Lecidea friabilis Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss. Kl. 104: 302 (1941).

Lectotype: New Zealand. Sine loco [probably Wellington], Charles Knight s.n. – BM [fide Hertel (1984b: 448)]. Isolectotype – M.

Lecidea gallinarum. Lectotype: New Zealand. Northland, Hen I., 2 m above high tide on basaltic rock, 13.xi.1933, L.M. Cranwell [ZA 413] – W [fide Hertel (1984b: 448)]. Isolectotype: Ibid., L.M. Cranwell [ZA 413] – CHR 347050. Paratypes: Ibid. L.M. Cranwell [ZA 416] – BM, CHR 347051.

Lecidea allanii. Holotype: New Zealand. Auckland, Rangitoto I., on lava, 22.viii.1933, H.H. Allan 90 – W. Isotype – CHR 347010.

Lecidea circumdiluens. Holotype: New Zealand. Wellington, south side of Wellington Harbour, Colenso 6544 – BM. Isotype – H-NYL 20101.

Lecidea friabilis. Isotype: New Zealand. Otago, Abbott's Hill Dunedin, on rock, J.S. Thomson T 977 [ZA 3650] – CHR 347045.

Descriptions : Flora (1985: 224 – as Lecidea allanii; 227–228 – as Lecidea circumdiluens; 232 – as Lecidea gallinarum).

Chemistry : Thallus K+ yellow, C+ orange, KC+ orange, Pd−; containing atranorin, arthothelin and thiophanic acid (Rambold 1989: 319). Lumbsch & Elix (2004: 55) give the chemistry as arthothelin (major), atranorin (major), zeorin (major), chloroatranorin (minor) and 4,5-dichlorolichexanthone (minor).

N: Northland (Whale I., Fanal I., Kawakawa Bay, Hen I., N of Warkworth, Leigh,), Auckland (Waitakere coast, Rangitoto), South Auckland (Great Mercury I., Hot Water Beach, Whitianga, Slipper I.), Gisborne (Waihau Bay) to Wellington. S: Marlborough (White's Bay); Canterbury (Banks Peninsula), Otago (Abbott's Hill, Dunedin, Nugget Point). On coastal rocks. Known also from Australia, though the provenance of the sole record (Lecidea insulana Müll.Arg.) is in doubt (Rambold 1989: 319–320; McCarthy 2003c, 2006) and from the Galapagos Is, Norfolk Is and Tasmania (Hertel 1989; Lumbsch & Elix 2004).

Palaeotropical

Exsiccati : Hertel (1985a: No. 146); Moberg (1996: No. 175).

Lecanora subcoarctata is characterised by: the saxicolous habit; the chinky, areolate, dingy whitish grey or creamish thallus; scattered apothecia with dark-brown to black, grey-pruinose to epruinose discs and pale-brown, waxy thalline exciple; the colourless hymenium, 40–45 μm tall; the green-black epithecium; oval–ellipsoidal ascospores, (8.5–)10–12 × 5–7(–8.5) μm; and a chemistry of atranorin, arthothelin and thiophanic acid. It is similar to L. austrooceanica (q.v. for further discussion of differences between these two taxa).