Parmotrema austrocetratum
Family
Parmeliaceae
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/saxicolous habit; the development of laminal dactyls, the upper surface becoming deeply areolate, the areolae ultimately flaking off and exposing the white medulla.
Distribution
North Island: Northland (Whangarei, Kawau Island), South Auckland (Kauaeranga River Coromandel Peninsula, Waihi Beach, Ohope Beach), Gisborne (Hicks Bay, East Cape), Taranaki (New Plymouth). South Island: Nelson (Puponga).
Known also from Papua New Guinea, the Philippines, Australia, New Caledonia, Norfolk Island and Lord Howe Island.
Habitat
On trees and shrubs (twigs) in northern, coastal forest and on coastal rocks.
Detailed description
Thallus loosely attached, pale green-grey to mineral-grey, 6–12 cm diam. Lobes rounded, imbricate or not, 10–20 (–30) mm wide, apices often laciniate, the laciniae flat or convex, 0.5–1.5 mm diam., 1–5(–8) mm long, moderately ciliate, cilia 0.2–1(–1.5) mm long, simple or sparingly branched. Upper surface white-reticulate at first (×10 lens) but becoming markedly cracked to the margins, developing closed, raised dactyls, dactyls ±curved, laminal, ultimately becoming fused with the formation of laminal ridges, older parts of thallus eventually becoming areolate, the areolae flaking off and exposing the white medulla in eroded areas; without isidia or soredia. Lower surface black, with a naked, brown, marginal zone 1–2 mm wide; moderately to densely rhizinate, rhizines simple or sparsely branched, slender, black. Apothecia rare, pedicellate, to 10 mm diam., disc perforate, pale-tan, concave at first then concave–distorted, margins eciliate, thin, stellate-cracked. Ascospores colourless, ellipsoidal, 12–16 × 8–9 μm. Pycnidia scattered, punctiform, black. Conidia filiform, 9–16 × 1 μm.
Chemistry: Cortex K+ yellow; medulla K+ yellow→red, C− KC+ red, Pd+ red-orange; containing atranorin, chloroatranorin, salazinic acid (major), consalazinic acid (minor) and ±protocetraric acid (tr.).
Similar taxa
It is distinguished from the related Parmotrema cetratum by the development of laminal dactyls, in being rarely fertile, more loosely adnate, and by having a distinct, naked brown, marginal zone on the underside of the lobes.
Substrate
Corticolous, saxicolous
Attribution
Fact sheet prepared by Marley Ford (13 December 2021). Brief description, Distribution, Habitat, Features and Similar taxa 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