Flora of New Zealand Series

Description : Thallus crustose, thick, in small clumps or patches, or in bands in crevices, to widespreading in continuous patches (0.5–)1–5(–8) cm diam., areolate, on a stringy to byssoid, white prothallus, visible between widely separated areolae or at the margins, sometimes, in deeply shaded habitats, extending to 1 cm beyond the areolae. Areolae rounded to irregular, angular, separated by narrow to deep cracks, or tightly crowded–conglomerate, (0.5–)1–3(–5) mm diam.,verrucose to squamulose to distinctly swollen and hummocky or blister-like to convoluted–cerebriform, eventually becoming subfruticose. Upper surface matt to slightly glossy, smoothly rounded to somewhat lumpy, pale olive-green to grey-green, or pale fawnish or creamish on surfaces exposed to light, white below, with or without soredia. Soralia round to irregular, shallowly to deeply erose, 0.1–2 mm diam., developing initially at base and side of areolae, later occasionally eroding whole surface. Soredia whitish, yellowish, greenish or dark-grey, farinose, C+ red (fleeting). Apothecia very rare. Pycnidia frequent, scattered to crowded, immersed, ostiole black, minute, slightly depressed. Conidia slender, slightly curved, colourless, 16–18 × 1 μm.

Chemistry : Thallus and soralia K+ yellow, C+ pinkish red to scarlet (often fleeting), Pd−; containing atranorin and alectorialic acid (Poelt & Leuckert 1984).

S: Otago (above Poolburn Reservoir, Manorburn, Old Man Ra., Mt Benger, Teviot River near Lake Onslow, Rock & Pillar Ra.). A high-alpine species occurring on siliceous rocks in deep cracks, small caverns and on the roofs of dry, shady underhangs of schist tors. A dry, rather specialised habitat, often together with Caloplaca lutea, Diploschistes spp., Lecanora bicincta, L. polytropa, L. swartzii, Protoparmelia badia, Ramalina fimbriata and species of Rhizocarpon (Galloway 2002b). Known also from Norway, Sweden, Russia, the Alps of Central Europe, Greenland, and Arizona in North America (Creveld 1981; Poelt & Leuckert 1984; Santesson 1993; Nash et al. 1998; Alstrup et al. 2000; Nimis & Martellos 2003; Alstrup 2004; Ryan et al. 2004b: 207–208).

Bipolar

Illustrations : Creveld (1981: 275, fig. 66a, b); Poelt & Leuckert (1984: 415, figs 1–5); Foucard (1990: fig. 132).

Lecanora cavicola is characterised by: the saxicolous habit (high-alpine underhangs and roofs of caverns); the olive-green-grey, rather hummocky thallus with a glossy to matt surface; greenish to whitish, farinose soralia (C+ red), and a fimbriate, white marginal prothallus. Its systematic position within Lecanora is still a matter of discussion (Poelt & Leuckert 1984).