Xanthoparmelia amplexula
Synonyms
Parmelia amplexula Stirt.
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 saxicolous habit; a foliose thallus; cylindrical isidia; a pale or brown lower surface; and the presence of norlobaridone and ±loxodin in the medulla.
Distribution
North Island: Auckland (Piha, Karekare). South Island: Nelson (St Arnaud, Lake Rotoiti), Canterbury (Cass), Otago (Cluden, Theatre Flats, Rockburn, Lamb Hill, Port Chalmers, Blackhead, Dunedin). Stewart Island.
Known also from Australia, Norfolk Island, Lord Howe Island, New Caledonia and South Africa.
Habitat
On coastal and inland (montane to subalpine) rocks
Detailed description
Thallus moderately adnate to adnate on rock, rarely on decorticated wood or soil, 5–10 cm diam. Lobes sparingly imbricate or not, subirregular to sublinear-elongate, irregularly branched, 0.8–2(–3) mm wide, central laciniae flat or absent. Upper surface yellow-green, darkening or blackened towards centre (because of dark-tipped isidia), matt, emaculate, smooth, without areolae or soredia, isidiate. Isidia sparse to densely developed, cylindrical, simple to branched or coralloid, to 2 mm tall, apices syncorticate. Lower surface pale-brown to dark-brown, rhizinate. Rhizines sparse to moderately dense, slender, concolorous with lower surface. Apothecia rare, subpedicellate, 1–5–6 mm diam., disc strongly concave to plane, glossy, dark-brown; thalline exciple thin, persistent, isidiate. Ascospores 7–12 × 5–6 μm. Pycnidia rare. Conidia bifusiform, 6–7 × 0.5 μm.
Chemistry: Cortex K−; medulla K−, C−, KC+ rose-pink, Pd−; containing usnic acid ±loxodin, norlobaridone (major), ±scabrosin 4,4’-diacetate, ±scabrosin 4-acetate 4’-butyrate, ±scabrosin 4,4’-dibutyrate, ±scabrosin 4-acetate 4’-hexanoate; rarely traces of norlobariol, isonorlobaridone, norlobariol methyl ester, connorlobaridone, constipatic and protoconstipatic acid.
Similar taxa
It is often confused with Xanthoparmelia scabrosa but differs in the nature of the isidia – X. amplexula has slender, syncorticate, cylindrical isidia which may or may not be branched, whereas in X. scabrosa the isidia are epicorticate, warty or globose, become inflated at the apices, and are at length erumpent.
Substrate
Saxicolous
Attribution
Fact sheet prepared by Marley Ford (6 February 2024). 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.