Flora of New Zealand Series

≡Lecidea laeta Stirt., Trans. N. Z. Inst. 30: 384 (1898).

Description : Thallus effuse or not apparent, grey-white or glaucous greyish, granular-papillate to areolate, areolae convex, minutely papillate, often eroded or lacking, not sorediate, in patches 5–30 mm diam. Prothallus absent. Apothecia prominent, scattered to crowded, biatorine, sessile, (0.1–)0.5–1(–2) mm diam., rounded to contorted-conglomerate, disc convex, matt, smooth to subplicate, waxy, orange-red to cinnabar-red; proper margin thin, entire, concolorous with disc or slightly paler. Epithecium densely granular, heavily conglutinate, orange-red, 10–15 μm thick. Hymenium 65–80 μm tall, pale-orange to hyaline, densely streaked with orange-red granules and richly inspersed with oil droplets. Paraphyses densely conglutinate, septate, not branched, 2–3 μm thick, apices not, or only very slightly, swollen. Asci clavate or cylindrical-clavate, 30–36 × 6.8–8.5 μm, 8-spored. Ascospores narrowly cylindrical, with a very thin, pseudoseptum developing towards one end of the spore, (10–)11.5–13.5(–19) × (1.5–)3–4(–7) μm.

Chemistry : Thallus K−; apothecia K+ reddish purple; containing parietin.

N: Northland (Little Barrier I.), Wellington (Tongariro National Park, Rangipo Desert). S: Nelson (Cobb Valley, Lake Rotoiti), Canterbury (Arthur's Pass, Hawdon River Cass), Otago (Rees Valley, Mt Teviot, Blue Mts, Swampy Hill Dunedin, Wairongoa), Southland (Awarua Bog). On decorticated wood (dead terminal twigs) of Coprosma, Dracophyllum, Hebe, Leptospermum scoparium, Melicytus alpinus, Podocarpus totara and smooth bark of Nothofagus solandri var. cliffortioides. Known also from Tasmania and Australia (Hafellner 1993; Filson 1996; McCarthy 2003c, 2006) and on Nothofagus bark in forests of Tierra del Fuego (unpublished observations). In some places it appears to be a rapid and early coloniser, as dead terminal twigs of small bushes of Leptospermum scoparium developed on a surface burned 17 years ago (Awarua Bog) supported reasonably large numbers of thalli that comprised the major lichen cover for this substratum.

Austral

Exsiccati : Vězda (1999a: No. 389).

Illustrations : Babington (1855: pl. CXXIX, fig. C – as Biatora cinnabarina); Lindsay (1866b: pl. LXIII, fig. 31 – as Lecidea cinnabarina); Malcolm & Galloway (1997: 108, 123, 141); Lumbsch et al. (2001: 21).

Pyrrhospora laeta is characterised by: the corticolous habit; the grey-white to glaucous-grey, continuous to ±granular-papillate or ±areolate thallus, which is often eroded or lacking; the scattered to clustered small, rounded, orange-red (K+ purple) apothecia, 0.1–1 mm diam., with thin, entire to subcrenulate, concolorous margins; and narrowly cylindrical ascospores, 10–19 × 1.5–4(–7) μm. Lauder Lindsay (1866b: 545) remarked of it: "One of the most beautiful corticolous Lecideae of any country. Apothecia of a bright vermilion-red; they resemble those of some forms of Lecanora ferruginea."