Flora of New Zealand Series

≡Lecidea crassilabra Müll.Arg., Hedwigia 32: 127 (1893).

Description : Thallus thin (to 0.3 mm thick), verrucose to evanescent, in patches to 70 mm diam.. Upper surface areolate, areolae irregular to angular, 0.5–1 mm diam., whitish to pale-grey, sometimes rusty-oxydated, surface roughened. Medulla I−. Apothecia rounded to angular, scattered or crowded, sessile, constricted at base, 0.6–1(–1.3) mm diam. Disc plane, black, matt, epruinose, margins distinct at first, persistent to occluded, concolorous with disc, rarely shining. Hypothecium dark-brown in basal part (K+ violet-brown), 120–250 μm thick, subhymenial layer colourless, 10–25 μm thick. Hymenium 65–80 μm tall, I+ blue; epithecium brownish green, 10–15 μm thick; paraphyses occasionally branched and anastomosing, 2 μm wide, apices thickened to 3–4 μm thick. Asci 50–65 × 11–13 μm, tholus 5–12 μm thick. Ascospores ellipsoidal, (10–)11–14(–15) × 5–6(–7) μm. Pycnidia immersed. Conidia (9–)9.5(–12) × 1 μm.

Chemistry : Thallus K−, C− KC−, Pd+ orange; containing stictic acid.

S: Nelson (Mt Aorere, Cobb Valley), Otago (Lake Alta and Double Cone, Remarkables, Old Man Ra., Rock & Pillar Ra., Maungatua) (Hertel 2001). On high-alpine rocks, often periodically inundated or near drainage cracks. Often associating with Cetrariella delisei. Known also from Australia (Rambold 1989; McCarthy 2003c, 2006) and Patagonia (Hertel 1997). First recorded in New Zealand from the Old Man Ra. Where it occurs "…on loose schist rocks, probably often at least partly inundated, immediately at the foot of a perpendicular rock wall of a high rock tower ("tor"), and within the area, where the dripping water from the top of the tor splashes. With associated Cetraria delisei, in a tundra-like vegetation" (Hertel 1992b).

Austral

Exsiccati : Hertel (1992b: No. 266 – as Lecidea crassilabra).

Lecidea lygomma var. crassilabra is characterised by: the saxicolous habit; a relatively thin thallus; sessile apothecia; the rather broad ascospores; the I+ blue hymenium; the K + violet-brown basal part of the hypothecium; a non-amyloid medulla; and stictic acid as the major lichen compound (Rambold 1989: 207). It is separated from L. lygomma, mainly on the thickness of the thallus (up to 1.2 mm thick in L. lygomma and up to 0.3 mm thick in L. lygomma var. crassilabra) and in chemistry (norstictic acid in L. lygomma).