Byssoloma subdiscordans
Synonyms
Byssoloma rotuliforme, Chiodecton subdiscordans, Patellaria rotuliformis
Family
Pilocarpaceae
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 foliicolous habit; the whitish to whitish green, warty thallus; black apothecial discs with white, byssoid margins; and 3-septate ascospores, 10–17 × 3–5 μm.
Distribution
North Island: Auckland (Waitakere Ranges), South Auckland (Hunua Ranges), Wellington (Kitchener Park, Feilding). South Island: Westland (NW of Lake Kanieri).
Widely distributed in tropical and subtropical regions. Known also from the west of Ireland and in Central and Southern Europe, where it colonises damp rocks and twigs and stems of Calluna, and recently recorded from British Columbia and Réunion.
Habitat
On leaves of Beilschmiedia tawa, Podocarpus totara, Pseudopanax crassifolius and Pseudowintera colorata.
Detailed description
Thallus to 4 cm diam., scattered, formed of small (0.2-0.4 mm diam.) irregular patches, in central parts often continuous, white or pale greenish-grey, slightly shining, prothallus absent, foliicolous. Apothecia sessile, margins irregularly circular, sometimes confluent, 0.3-0.6 mm diam., distinctly byssoid, disc black, epruinose, plane to subconvex. Ascospores irregularly arranged, 3-septate, ellipsoid, 10-17 × 3-5 µm. Pycnidia rare, sessile, ± globose, 0.05-0.15 mm diam. Conidia simple, flask-shaped, 4-5 × 1.5-2 µm.
Chemistry: Characterised by the presence of the 2,5,7-trichloro-3-O-methylnorlichexanthone chemosyndrome including: vinetorin (tr.), 5,7-dichloro-3-O-methylnorlichexanthone (major), 4-O-methylasemone (minor), 3-O-methylthiophanic acid (tr.), 2,5,7-trichloro-3-O-methylnorlichexanthone (major) and, 5,7-dichloro-6-O-methylnorlichexanthone (minor).
Similar taxa
Byssoloma subdiscordans is distinguished from B. leucoblepharum and B. subundulatum by its black rather than brown apothecia.
Substrate
Foliicolous (leaves)
Attribution
Fact sheet prepared by Melissa Hutchison (12 February 2022). Brief description, Distribution, Habitat, and Features 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.