Flora of New Zealand Series

≡Lecidea effugiens Nilson, Die Flechtenvegetation des Sarekgeb.: 27 (1907).

Description : Thallus crustose, areolate, to 1 mm thick and in patches to 8 cm diam. Prothallus black, visible between areolae and sometimes well-developed and prominent at margins forming a thick, black felted zone 0.5–3 mm wide. Areolae very small, (0.05–)0.1–0.2 mm diam., crowded, flat to subconvex, matt, greyish or dirty creamish. Apothecia sessile, solitary or in small groups, (0.05–)0.2–0.4(–0.8) mm diam., disc black, matt, plane to convex, becoming conglomerate, epruinose. Proper exciple persistent, to 0.05 mm wide, concolorous with disc. Epithecium bright-green to green-black, 10–15 μm thick. Hymenium colourless except for upper parts, 55–70 μm tall. Hypothecium reddish brown. Paraphyses simple, rarely branched and anastomosing, 1.5–2 μm thick, apical cells to 4 μm diam. Asci clavate, 50–65 × 12–15 μm. Ascospores broadly ellipsoidal, 10–16(–20) × 6–9 μm. Pycnidia not seen.

Chemistry : Thallus K− or + pale-yellow, C−, KC+ strongly orange, Pd−; containing atranorin, isoarthothelin, aotearone, dichlorolichenxanthone (tr.) and zeorin (Hertel 1992a: 7).

S: Otago (Little Valley E of Alexandra, Flat Top Hill, Umbrella Mts above Gem Lake). On loose schist plates lying on ground in an area heavily grazed and manured by rabbits and dominated by Thymus vulgaris (Hertel 1992a: 7), and also on flat schist plates in alpine grassland, associating with Lecanora polytropa, Lecidea fuscoatrula, Porpidia macrocarpa and Rhizocarpon grande. Known also from Great Britain, Europe, Scandinavia, Iceland, Greenland Svalbard, Asia, and North and South America (Knoph et al. 1995a: 49, fig. 4; Nimis & Martellos 2003; Knoph & Leuckert 2004).

Cosmopolitan

Exsiccati : Hertel (1992a: No. 250).

Lecidella effugiens is characterised by: the saxicolous habit; thalli strongly delimited by a prominent, black, marginal prothallus, and forming mosaics; small, black apothecia, 0.05–0.4 mm diam.; a bright-green to green-black epithecium; a reddish brown hypothecium; broadly ellipsoidal ascospores, 50–65 × 12–15 μm; and a KC+ orange thalline reation (isoarthothelin).