Ochrolechia xanthostoma
Synonyms
Porina xanthostoma Sommerf., Kongl. Pertusaria xanthostoma (Sommerf.) Fr.
Family
Ochrolechiaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Crustose
Current conservation status
2018 | Not Threatened | Qualifiers: SO
Brief description
Characterised by the muscicolous/terricolous habit; a thin, smooth, marginally unzoned, continuous, to granular–papillate, ashy-grey, white to creamish white thallus; numerous, concolorous poriform verrucae with sunken ostioles surrounded by a pinkish or yellow-brown border; clavate asci (soon deliquescing) with usually 4 thin-walled, uniseriate or biseriate ascospores; and a KC+ red medullary reaction indicating the presence of alectoronic acid.
Distribution
North Island: South Auckland (Te Aroha). South Island: Nelson (Mt Aorere, St Arnaud Range), Marlborough (Mt Stokes), Canterbury (Sugarloaf Cass, Craigieburn Range, Torlesse Range, Godley Valley), Otago (Humboldt Mountains, Old Man Range, Poolburn Reservoir, Mt Pisgah, Rock & Pillar Range Deep Stream). Stewart Island: (The Paps, Cooks Arm Port Pegasus). Campbell Island.
First described from Norway, it is known also from Alaska, Greenland, Iceland, Scotland and Western Russia. In the Southern Hemisphere it is known from New Zealand, Tasmania and Macquarie Island.
Habitat
A distinctive muscicolous/terricolous species found in subalpine to high-alpine environments overgrowing dead tussock bases, mosses and both living (e.g. Pentachondra pumila) and decaying vegetation on exposed soils.
Detailed description
Thallus off-white, ashy-grey, white or creamish white, thin, continuous, to granular–papillate, surface smooth and dull, overgrowing dead tussock bases, mosses, detritus and soil. Apothecia verruciform, concolorous with thallus, flattened–hemispherical, constricted at base, sometimes concave above, (0.1–)0.5–1.0 mm diam.; ostioles inconspicuous, 1–4 per verruca, hyaline to pale-yellow, yellow-brown or pinkish. Hypothecium hyaline to brownish. Epithecium K−, pale to dark. Asci clavate, often deliquescing before ascospores mature, (140–)220(–320) × 30–85 μm. Ascospores 4 per ascus (rarely 6–8 per ascus), uniseriate or biseriate, ellipsoidal to cylindrical, but often deformed and found liberated from ascus, 65–85 × 35–40 μm, walls double, thin, 1–2 μm thick, the inner wall smooth.
Chemistry: Medulla UV+ ice-blue, K−, KC+ red, C− or + pink, Pd−; containing alectoronic acid (major), and ursolic acid (tr.).
Substrate
Muscicolous, terricolous
Attribution
Fact sheet prepared by Marley Ford (10 January 2022). Brief description, Distribution, Habitat, and Features sections copied from Galloway (2007).
References and further reading
Galloway D.J. 2007: Flora of New Zealand: Lichens, including lichen-forming and lichenicolous fungi. 2nd edition. Lincoln, Manaaki Whenua Press. 2261 pp.