Pyxine subcinerea
Common name
Mustard lichen
Family
Caliciaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Foliose
Current conservation status
2018 | Not Threatened | Qualifiers: SO
Brief description
Characterised by the corticolous/lignicolous/saxicolous habit; the yellow medulla; marginal soralia; subapical, glistening patches of pruina; and lichexanthone (UV+ yellow) in the medulla.
Distribution
Kermadec Islands: Raoul Island (on Araucaria*, Citrus sinensis*, Prunus sp.*). North Island: Northland (Te Huka, Spirits Bay, Karikari Peninsula, Carpenter’s Bay, Poor Knights Islands, Chicken Island, Little Barrier Island, Whangarei, Goat Island near Leigh), Auckland (Anawhata, Auckland Domain), South Auckland (Coromandel Peninsula, Great Mercury Island, Whale Island). South Island: Marlborough (d’Urville Island).
Habitat
On bark of coastal trees and shrubs (Casuarina*, Coprosma, Corynocarpus laevigatus, Cordyline australis, Metrosideros excelsa) and on introduced deciduous trees, fence posts in grassland, and occasionally on maritime rocks. Widespread in the tropics. Also in the Azores and Liguria in Italy, and in the eastern United States.
Detailed description
Thallus closely attached, corticolous. Lobes pale greenish-grey to pale grey, plane, with marginal pseudocyphellae here and there pruinose subapically or more generally in pulverulent, glistening patches over upper surface. Soralia marginal, spreading onto upper surface, orbicular to irregularly ellipsoid excavate to ± convex, soredia fine, granular, white to pale yellowish. Medulla pale straw-coloured to ochraceous-yellow. Apothecia not seen.
Chemistry: Cortex UV+ yellow; medulla K-, Pd-, UV-. TLC: Lichexanthone.
Substrate
Corticolous, lignicolous (fence posts), saxicolous (maritime rocks)
Attribution
Fact sheet prepared by Melissa Hutchison (3 August 2022). 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.