Lecidea lygommella Elix
Mycobank MB 517792
Thallus saxicolous, verrucose to evanescent, up to 7 cm wide, 0.2–0.7 mm thick. Upper surface whitish to pale grey or rusty red-brown, areolate, areoles irregular to angular, 0.5–1.0 mm wide, flat, surface roughened or ±smooth; cortex 20–50 µm thick, upper cell layer unpigmented to grey-brown. Photobiont layer 70–100 µm thick, algal cells 9–16 µm wide. Medulla I–. Hypothallus dark grey, sometimes obvious at the thallus margin but often not developed. Apothecia scattered or crowded, rounded to angular, subimmersed to adnate, rarely basally constricted, 0.5–2.3 mm wide; disc black, flat to slightly convex, matt, epruinose or with rusty, red-brown pruina, margin concolorus with disc, distict at first, persistent or excluded with age, rarely shiny. Hypothecium dark brown to black-brown in basal part, K+ violet-brown, 120–250 µm thick. Hymenium colourless, 60–85 µm high, I+ blue. Epihymenium brownish green, 10–15 µm high, N+ red-violet (cinereorufa-green); paraphyses occasionally branched and anastomosing, ca. 2 µm wide, apices thickened to 3–4 µm wide. Asci 8-spored, 50–65 x 11–13 µm. Ascospores simple, ellipsoidal, colourless, 10–17 x 5–8 µm. Pycnidia immersed, ostiole black, punctiform; conidia bacilliform, 9–12 x 1 µm. Secondary chemistry: nil.
This species is characterized by the areolate, whitish to grey or rusty red-brown thallus, the I– medulla, the black, subimmersed to adnate apothecia, the dark brown to black-brown hypothecium and brownish green epihymenium; the relatively large ascospores and by the absence of lichen substances. Lecidea lygommella is morphologically very similar to L. lygomma, but the latter differs chemically in containing norstictic acid (major) and connorstictic acid (minor) (Rambold, 1989; Hertel, 1997). In the latter paper, Hertel commented that Lecidea lygomma with no TLC-detectable substance … presently must be treated as L. lygomma sensu lato.
The specific epithet refers to the similarity of this species to Lecidea lygomma Nyl.
At present this distinctive new species is known from rocks in alpine areas of New South Wales and Victoria.
Type:—AUSTRALIA: Victoria: Alpine National Park, Bogong High Plains, Basalt Hill, 20 km SE of Mt. Beauty; 36°53’S, 147°18’E, 1650 m; on basalt rocks in exposed alpine grassland with basalt outcrops; Feb 1994, Elix & Streimann 40407 (holotype CANB; isotypes Elix, Lichenes Australasici Exsiccati 284, as Lecidea lygomma).
Additional specimens examined (paratypes):— AUSTRALIA: New South Wales: Bulee Gap, 8 km NE of Nerriga, just S of Morton National Park; Elix 39721 (CANB). Kosciuszko National Park, Blue Lake, 7 km NE of Mt Kosciuszko, Streimann 9591 (CANB). Victoria: Alpine National Park, Bogong High Plains, Basalt Hill, 20 km SE of Mt. Beauty; Elix & Streimann 40443 (CANB), Elix & Streimann 40447 (B, CANB). Alpine National Park, Bogong High Plains, 20 km SSE of Mt. Beauty; Elix & Streimann 40477 (CANB). 'Ruined Castle', Bogong High Plains, 16.5 km SSE of Mt. Beauty; Elix & Streimann 40616 (CANB).
Sicut Lecidea lygomma sed acida lichenum deficiente differt.