AUSTROMELANELIXIA ¹

Gintaras Kantvilas ²

Austromelanelixia Divakar, Crespo & Lumbsch, Fungal Diversity 84: 110 (2017).

Type: A. piliferella (Essl.) Divakar, Crespo & Lumbsch

Thallus foliose, with lobes flattened, dorsiventral, plane to concave; upper surface a shade of olive to dark chestnut-brown, N± reddish brown, maculate, corticate, with a pored epicortex, sometimes with cortical hairs, lacking cilia and pseudocyphellae; lower surface brown to black, with simple rhizines. Photobiont trebouxioid. Ascomata apothecia, lecanorine, laminal; disc plane to concave, pale to dark brown; proper exciple cupulate. Asci 8-spored, of the Lecanora-type: clavate, with a well-developed, amyloid tholus, pierced entirely by a narrow, non-amyloid masse axiale with parallel flanks; ocular chamber not developed. Paraphyses rather stout, straight, sparsely branched; apices slightly swollen. Ascospores simple, hyaline, ellipsoid to ovoid. Conidiomata pycnidia, immersed, laminal; conidia bifusiform. Chemistry: depsides (gyrophoric acid and related compounds).

Austromelanelixia is a genus of the “brown Parmeliae” consisting of five, exclusively Southern Hemisphere species. It was segregated from the related Northern Hemisphere genus Melanelixia chiefly on the basis of molecular data (Divakar et al. 2017). In Tasmania, species of Austromelanelixia are most likely to be confused with brown species of Xanthoparmelia (formerly classified in Neofuscelia). These differ chiefly by their N+ bluish green cortical reaction, although there are additional anatomical and chemical characters, mainly pertaining to the upper cortex, which further distinguish these genera.

Key references: Elix (1994); Kantvilas et al. (2002); Divakar et al. (2017).

1	Thallus with marginal and laminal soredia; a common epiphyte in wet forest, especially on canopy twigs in rainforest at high elevations	2 A. subglabra
	Thallus with terete isidia and scattered, minute, cortical hairs; rare on rocks in dry areas	1 A. piliferella

1 Austromelanelixia piliferella (Essl.) Divakar, Crespo & Lumbsch

Fungal Diversity 84: 111 (2017); —Parmelia piliferella Essl., J. Hattori Bot. Lab. 42: 83 (1977); Melanelia piliferella (Essl.) Essl., Mycotaxon 7: 48 (1978); Melanelixia piliferella (Essl.) Crespo, Divakar & Elix, Taxon 59: 1750 (2010).

Thallus tightly adnate, glossy chestnut-brown, to c. 3 cm wide; lobes plane, to 2 mm wide, discrete and rounded at the apices, crowded and imbricate in the thallus centre, sometimes minutely lobulate at the margins, isidiate; isidia cylindrical, simple or branched, to c. 0.5 tall and c. 0.05 mm wide, very abundant and forming a subcrustose mass in the centre of the thallus; cortical hairs present, minute, hyaline, 20–30 µm long, scattered on the upper surface and at the tips of the isidia. Apothecia and pycnidia unknown.

Chemistry: gyrophoric and 5-O-methylhiascic acids; medulla K–, KC+ red; C+ red, P–, UV–.

Very rare in Tasmania, known from a single collection from dry sandstone bluffs in the Southern Midlands, and consequently listed as “vulnerable” under the Tasmanian Threatened Species Protection Act 1995. Extensive investigations of this type of habitat over many decades have not revealed any futher localities. On the south-eastern Australian mainland, this species occurs on bark. It could easily be mistaken for any one of several, olive-brown, isidiate species of Xanthoparmelia, from which it is most easily distinguished by chemical characters (cortex N–; medulla C+ red).

Hunting Grounds, c. 4.5 km W of Dysart, 42°34’S 147°10’E, 1981, G. Kantvilas 480/81 & P.W. James (BM, HO).

2 Austromelanelixia subglabra (Räs.) Divakar, Crespo & Lumbsch

Fungal Diversity 84: 111 (2017); —Parmelia subaurifera var. subglabra Räs., Ann. Bot. Soc. Zool.-Bot. Fenn. Vanamo 2: 19 (1932); Parmelia subglabra (Räs.) Essl., Bryologist 76: 307 (1973), Melanelia subglabra (Räs.) Essl., Mycotaxon 7: 48 (1978); Melanelixia subglabra (Räs.) Crespo, Divakar & Elix, Taxon 59: 1750 (2010).

Thallus loosely adnate, glossy olive-grey to pale olive-brown, to c. 6 cm wide; lobes undulate to concave, with the margins upturned, to 5 mm wide, discrete and rounded at the apices, crowded and imbricate in the thallus centre, lacking cortical hairs, sorediate; soredia coarsely granular, sometimes becoming corticate and pseudoisidiate, white to pale greyish or ± concolorous with the upper surface, mainly marginal, occasionally also laminal, initially punctiform but often spreading and coalescing along the lobe margins. Apothecia unknown in Tasmania; ascospores reported as 14–18 × 8–10 µm (Elix 1994). Pycnidia unknown.

Chemistry: gyrophoric and 5-O-methylhiascic acids; medulla K–, KC+ red; C+ red, P–, UV–.

Widespread in high rainfall areas, especially at higher elevations, on smooth bark, such as the canopy limbs of rainforest trees and undershrubs. This species is also known from Victoria and southern South America.

N of Pine Lake, 41°43’S 146°43’E, 1973, G.C. Bratt 73/1092 (HO); Russells Road, Mt Maurice, 760 m, 1981, G. Kantvilas 71/81 (HO); Little Fisher River, 41°45’S 146°20’E, 820 m, 1982, G. Kantvilas 304/82 (HO).

References