Rusavskia elegans
Synonyms
Lichen elegans, Rusavskia elegans, Xanthoria elegans
Family
Teloschistaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Foliose
Current conservation status
2018 | At Risk – Naturally Uncommon | Qualifiers: RR, SO
Brief description
Characterised by the saxicolous habit; bright orange-red, rosette-forming thalli 3–6 cm diam., composed of radiating, narrow, convex lobes, 0.5–1 mm wide and 3–8(–10) mm long, not tapering from centre to apices, discrete or contiguous at margins and often to centre or ±imbricate centrally. Apothecia central, disc orange-red, margins persistent, thin, concolorous with thallus, without rhizines below. Forms vivid splashes of colour on rock, often among yellow-green patches of Rhizocarpon geographicum.
Distribution
South Island: Marlborough (Waihopai Valley), Canterbury (Craigieburn Range, Godley Valley, Ben Ohau Range), Otago (St Bathans Range, Dunstan Mts, Old Man Range, The Remarkables, Mt Benger, Umbrella Mts, Poolburn Reservoir, Rough Ridge, Rock & Pillar Range, Teviot Valley, Millers Flat).
A widespread, bipolar lichen with a wide ecological tolerance and a high degree of morphological variation. In South America it is known from the Andes (3,500 – 4,000 m), from Patagonia and Tierra del Fuego.” Published records include Italy, Spain, Great Britain, Scandinavia, United States and Canada, South Africa, East Africa, and Morocco. In northern Chile on the alteplano close to the Bolivian border it occurs on rock outcrops at 4500 m. In the South Pacific it is absent from both Australia and Tasmania, but is known from Macquarie Is. and Marion Is. It occurs widely in Antarctica.
Habitat
On subalpine to high-alpine rocks, also on concrete surfaces at lower elevations. Characteristically growing on steep to vertical rock walls and bluffs in nivation cirques, and on dry, upward-facing ledges and underhangs of schist tors which are a prominent feature of the flat-topped mountains of Central Otago. It also colonises concrete fenceposts, concrete telephone poles and sunny exposed surfaces of concrete retaining walls of some Central Otago irrigation dams (e.g. Falls Dam, Poolburn Reservoir). The species grows in both sunny and shaded sites, being largely snow-covered in winter months. It has an altitudinal range of 700–2000 m. It is still very much undercollected in New Zealand and its ecological requirements imperfectly known. It associates with other bipolar alpine lichens such as Lecanora cavicola and L. swartzii in sheltered crevices and overhangs in high-alpine sites on the Central Otago mountain summits, a habitat also supporting small populations of Ramalina fimbriata.
Detailed description
Thallus rosette-forming to irregularly spreading, often eroded or lacking in parts, to 6 cm diam., saxicolous. Lobes radiate, contiguous or partly imbricate and loosely attached, convex or subconvex, sparingly branched, c. 1 mm wide, margins crenate to subsinuous. Upper surface orange-red or red, smooth, matt, wrinkled or minutely faveolate or pitted centrally, without isidia, maculae, pseudocyphellae or soredia. Apothecia central, occasional, to 1.2 mm diam., disc red, margins persistent, rather thin, concolorous with thallus. Ascospores 10-13 × 6-8 µm. A rather constant species in New Zealand, varying only in thallus colour, depending on the light regime of the substratum, and in the degree of apothecial development. The cortical pigment parietin is an effective UV-B screening compound in this lichen.
Substrate
Saxicolous. Also on concrete (power poles, fenceposts, retaining walls).
Etymology
elegans: Elegant
Attribution
Fact sheet prepared by Melissa Hutchison (5 July 2021). Information in the Brief description, Distribution, Habitat, Features and Similar taxa sections copied from Galloway (1985, 2007).
References and further reading
Galloway D.J. 1985: Flora of New Zealand: Lichens. Wellington: PD Hasselberg, Government Printer. 662 pp.
Galloway D.J. 2007: Flora of New Zealand: Lichens, including lichen-forming and lichenicolous fungi. 2nd edition. Lincoln, Manaaki Whenua Press. 2261 pp.