Menegazzia dielsii
Synonyms
Parmelia dielsii
Family
Parmeliaceae
Flora category
Lichen – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Lichens - Foliose
Current conservation status
2018 | Not Threatened
Brief description
Characterised by the corticolous habit; pruinose apothecial discs; a densely granular epithecium, and 8-spored asci. It is the only species of the genus in New Zealand with pruinose apothecial discs. Occasionally the pruina is poorly developed but is usually present on discs of young apothecia. It is also the only species of the genus in New Zealand with psoromic acid in the medulla (K+ yellow).
Distribution
North Island: S of latitude 38ºS (Lake Waikaremoana). South Island: Nelson-Marborough (Omaka Valley), Canterbury (Arthur’s Pass to Lake Ohau), Otago (Rees Valley, Lake Howden, Maungatua) to Fiordland. Stewart Island: (Mt Anglem, Glory Cove).
Habitat
On beech bark in beech forest, and on mossy rocks and subalpine scrub, s.l. to 1000 m.
Detailed description
Thallus closely attached forming irregular, complete or partial rosettes, or irregularly encircling twigs and small branches, to 15 cm diam., seldom exceeding 10 cm diam., sometimes coalescing to form extensive, spreading colonies, texture rather soft and pliable to ± rigid, corticolous. Lobes numerous, shortly radiating at outer edges, medium, rather uniform, 2.0-2.8 mm wide, ± distinct from margins to centre, or obliterated by numerous, overlapping secondary lobes, terminal lobes irregularly or subdichotomously branched, sometimes palmate, contiguous throughout or occasionally ± discrete towards edges of thallus, becoming laterally compressed, compacted and contorted especially at centre, margins entire, sinuous-contorted, almost zig-zag interlocked, with few, short, interstitial laterals throughout, or more rarely, developing numerous laterals, not or sparingly blackened, apices concolorous, not suffused brownish, hollow, lower side of internal cavity white or grey. Upper surface uneven but mainly convex, pale grey, emaculate, smooth, even or commonly rugose-uneven, rarely transversely ridged, ± shining, without isidia or soredia. Perforations few to frequent, median, mainly on main lobes, 0.5-1(-1.5) mm diam., rounded or elliptical, rather variable, either gaping with a depressed margin (pertransita-type), or ± elevated not conical. Apothecia common, scattered or 2-3-contiguous, or sometimes clustered, sessile to shortly pedicellate, cupuliform to ± plane, margins regular to angular, thin, even, or thick, subcrenate, smooth or striate-lacerate, ± shining, naked or matt and ± white-pruinose, disc concave, brown or red-brown, ± densely white-pruinose, rarely ± glabrous. Epithecium dull brown, ± red-brown or colourless, densely granular, granules minute, forming an encrusting layer but not penetrating deeply into hymenium below. Hymenium 130-160 µm tall. Asci 8-spored, ovoid to turbinate, sometimes ± abruptly truncate towards apex, 85-95 × 38-41 µm. Ascospores ellipsoid or oval, 30-39(-42) × 20-23(-26) µm, wall 2 µm thick.
Chemistry: Medulla K+ yellow, C−, KC−, Pd+ orange; containing atranorin (cortex), psoromic, conpsoromic and echinocarpic acids.
Similar taxa
The epithecium is densely granular as in Menegazzia lucens; however, the UV− medulla and the 8-spored asci distinguish it from this species.
An undescribed taxon with pruinose apothecial discs and containing stictic, constictic and galbinic acids is known from Mt Cargill, Cascade Cove (Fiordland) and Stewart Island (Mt Anglem, Glory Cove) [D. Galloway, unpublished observations].
Substrate
Corticolous
Attribution
Fact sheet prepared by Melissa Hutchison (February 2023). 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.