Coenogonium flavum
Synonyms
Dimerella flava Malcolm & Vězda
Family
Coenogoniaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Crustose
Current conservation status
2018 | Data Deficient | Qualifiers: SO
Brief description
Characterised by the foliicolous habit; the relatively large, pale-yellow apothecia, soon immarginate, constricted at base or subpedicellate, mostly growing on underside of leaves or colonising thin twigs; and the remarkable, tapering, tubular pycnidia, pale-yellow as the apothecia, and clothing the photobiont-containing thallus on upper surface of leaves, rarely on thin twigs. Conidiophores line walls of basal cavity of the pycnidial tube, shedding copious conidia, which exude from the tip of the tube, characters not before seen in Coenogonium.
Distribution
North Island: Wainuiomata. South Island: Nelson (Brook Stream, Pelorus Bridge, Buller Gorge).
Known also from Brazil (W.M. Malcolm pers. comm.).
Habitat
On leaves of Beilschmiedia tawa, Austroblechnum colensoi and Icarus filiformis.
Detailed description
Thallus crustose, epiphyllous, continuous, olive-green, shiny, the prothallus not at all distinct, up to 0.5 mm thick, ecorticate. Photobiont green, Trentepohlia. Apothecia hypophyllous or rarely epiphyllous, orbicular, strongly constricted at base or subpedicellate, 0.8–1.0 mm diam., 0.25 mm high, pale-yellow, the disc plane, margins slightly elevated at first, soon excluded. Exciple coarsely paraplectenchymatous, hyaline. Hymenium hyaline, 50–55 μm tall. Paraphyses straight, simple, to 1.8 μm diam., apices swollen, capitate-globose, to 5 μm diam. Asci cylindrical. Ascospores uniseriate, ellipsoidal, 8–9 × 3 μm. Pycnidia epiphyllous, tubular, 1.2–1.75 mm tall, pale-yellow, tapering toward apex, 0.15 mm wide at base and 0.05 mm below apex, with a terminal club-shaped mass of pale-yellow conidia. Conidiophores 7–10 μm long, 1.5 μm wide, covering walls of the cavity in the basal part of the tube and producing copious conidia. Conidia, short-ellipsoidal, simple but often spuriously 1-septate, 3.3–3.5 × 1.8–2 μm.
Substrate
Foliicolous
Attribution
Fact sheet prepared by Marley Ford (16 February 2024). 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.