Leiorreuma exaltatum
Synonyms
Lecanactis exaltata, Phaeographis exaltata
Family
Graphidaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Crustose
Current conservation status
2018 | At Risk – Naturally Uncommon | Qualifiers: DP, SO
Brief description
Characterised by the corticolous habit; a rather thick, grey to creamish grey thallus; flexuose, stellate or short and circular lirellae, often with thin, lateral thalline intrusions; a black to grey-pruinose disc; 6-locular ascospores, 22–38 × 10–12 μm; and no secondary chemistry.
Distribution
North Island: South Auckland (Mt Moehau, Coromandel Range), Wellington (W slopes of Tararua Ranges). South Island: Nelson (Tophouse, Lead Hills), Westland (Greymouth), Otago (Lake Howden, Leith Saddle Dunedin), Southland (Doubtful Sound). Stewart Island.
Known also from Mexico, Dominica, Brazil (Wirth & Hale 1963, 1978; Aptroot 2002e), Hawai’i, Japan, Sabah, Malesia, Java, the Philippines (Magnusson 1955; Nakanishi 1966; Hayward 1977; Staiger 2002; Kurokawa 2003; Nakanishi et al. 2003), mainland Australia and Tasmania.
Habitat
Often on bark of beech (Fuscospora spp., Lophozonia menziesii) trees, montane, lowland and coastal, s.l. to 800 m.
Detailed description
Thallus thick, pale, dull white, corticolous. Lirellae prominent 1-6 × 0.3-0.6 mm, irregular, branched and flexuous, sometimes stellate, often with thalline margin interrupting and breaking one fruit into several, proper exciple open, base carbonised, thalline margin distinct, often raised, disc plane, black or faintly pruinose and grey. Ascospores 8 per ascus, 6-locular, 20-30 × 8-10 µm, with thick, dark walls, younger spores brown, darkening and wrinkling with age.
Chemistry: TLC−, all reactions negative.
Substrate
Corticolous
Leiorreuma is a genus of c. 7 species included in the family Graphidaceae. It is characterised by lirellae of variable shape, with a prominent thalline margin that sometimes breaks across the hymenium forming smaller, circular apothecia; a carbonised exciple that is continuous below the hymenium forming a thick, carbonised hypothecium; 8-spored, Graphis-type asci; and brownish, transversely septate, thick-walled ascospores. It occurs in both tropical and temperate biomes. One species is known from New Zealand.
Attribution
Fact sheet prepared by Melissa Hutchison (3 September 2021). Brief description, Distribution, Habitat, Features, and Extra information 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.