AINOA ¹²

Gintaras Kantvilas ³

Ainoa Lumbsch & I.Schmitt, Mycol. Res. 105: 272 (2001).

Type: A. geochroa (Körb.) Lumbsch & I.Schmitt

Thallus crustose, ecorticate. Photobiont a unicellular green alga with ± globose cells 10–20 µm wide. Ascomata apothecia, biatorine, sessile, basally constricted. Proper exciple thick and prominent, persistent, concolorous with the disc or a little paler, in section cupulate, dark red-brown, composed of richly branched and anastomosed, entangled, long-celled, thick-walled hyphae 2–4 µm thick. Hymenium hyaline, non-amyloid, inspersed with scattered, large oil droplets. Asci cylindrical to elongate-clavate with a rather extended ’tail’, 8-spored, of the Baeomyces-type: non-amyloid, with a thin tholus at least when young and the ascoplasm rounded to truncate; ocular chamber absent. Paraphyses richly branched and anastomosed, entangled, slender, separating readily in water and K; apices not swollen. Ascospores simple, hyaline, ellipsoid, non-halonate, thin-walled, typically with a large vacuole. Conidiomata pycnidia, immersed. Conidia filiform. Chemistry: gyrophoric acid, restricted to the apothecia and pycnidia.

A genus of three species, occurring in cool temperate areas of both hemispheres. Although formerly included in the Trapeliaceae on account of superficial similarities in morphology and ascus type, molecular data indicate that its relationships lie with the Baeomycetaceae. Ainoa is distinguished from Trapelia and Trapeliopsis by the robust, persistent, single-layered exciple composed of thick-walled hyphae. In Trapelia, the exciple is highly reduced and composed of thin-walled hyphae, whereas in Trapeliopsis, although well-developed, it is composed of thin-walled hyphae and has an inner prosoplectenchymatous layer and an outer paraplectenchymatous layer.

Key references: Coppins & James (1984); Lumbsch et al. (2001); Brodo & Lendemer (2015).

1 Ainoa mooreana (Carroll) Lumbsch & I.Schmitt

Mycol. Res. 105: 273 (2001); —Lecidea mooreana Carroll, Nat. Hist. Rev. 6: 529 (1859); Trapelia mooreana (Carroll) P.James in H. Hertel, Herzogia 3: 404 (1975).

Thallus areolate to ± granular, pale to deep orange-brown, or abraded and pale grey, to 0.5–1 mm thick, forming irregular, continuous or rather dispersed patches that can extend over 10s of centimetres of pebbly ground. Apothecia 0.5–1 mm wide; disc plane to concave, dark brown to black, proper exciple in section 25–50 µm thick. Hypothecium hyaline to pale brown, 80–100 µm thick. Hymenium 100–130 µm thick, with a dilute pale greenish grey to olive-brown, K+ olive-green epithecial layer; asci 85–100 × 10–15 µm; paraphyses 0.8–1 µm thick. Ascospores usually uniseriate, 13–15.2–18 × 5–6.4–8 µm. Pycnidia not found; conidia reported (Coppins & James 1984) as 5–6 × 0.7 µm.

Chemistry: gyrophoric acid in the apothecia; apothecial sections K–, KC+ red, C+ red, P–.

Widely scattered on siliceous rocks in cool, moist environments in both hemispheres, although not recorded for mainland Australia. In Tasmania, it typically occurs on scattered pebbles in open ground, such as gravelly roadsides, or in gaps, frost hollows or dried up shallow puddles, especially at higher elevations. It is easily recognised macroscopically by its relatively thick, areolate, orange-tinted thallus with prominent, mostly dark, persistently marginate apothecia, and anatomically by the distinctive asci. There are several superficially similar crustose lichens in such habitats, but most of these belong to the Trapeliaceae, Porpidiaceae or Lecideaceae.

Mt Field, 42°39’S 146°35’E, 1968, J.E.S. Townrow (HO); c. 2 km NW of Trial Harbour, 41°55’S 145°11’E, 200 m, 1989, G. Kantvilas 143/01 (HO, M); Grey Mountain, 43°06’S 147°07’E, 810 m, 2018, G. Kantvilas 13/18 (HO, NY, UPS).

References