Usnea dasaea
Synonyms
Usnea undulata
Family
Parmeliaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Fruticose
Current conservation status
Not Evaluated
Brief description
Characterised by the presence of dense spinulose fibrils that can detach easily, leaving a slightly raised scar or fibercle on which soralia can develop, and the presence of salazinic, norstictic and galbinic acids.
Distribution
North Island: Northland (Hokianga, Whangarei), Auckland, Coromandel, Hamilton, Waitomo. South Island: Nelson, Banks Peninsula, Otago. It often is confused with U. rubicunda and U. cornuta, so an examination of material from New Zealand herbaria is likely to show that it is widespread.
Also known from North America, South America, Europe and Asia and Australasia.
Habitat
The species has been collected from sea level to 807 m elevation from several sites in Northland, Auckland, Waikato, Whanganui-Manawatu, Tasman and Otago. So far, it is known from coastal pohutukawa (Metrosideros excelsa) forest, inland mixed broadleaf native forest, and a range of native and introduced trees and shrubs in suburban settings. It commonly occurs with Usnea rubicunda.
Detailed description
Thallus grey-green to yellow-green, shrubby to subpendent, to 10–15 cm long; branching mixed isotomic/anisotomic; lower branches not constricted at the origin; smaller branches appearing slightly constricted at the origin, but articular cracks can mimic constrictions; trunk short, not pigmented; lower branches slightly inflated, terete to slightly ridged, foveoles present or absent, cylindrical, tapering, tips of branches tapering, articular cracks on branches few but typical at smaller branch origins; papillae seen on some specimens; spinulose fibrils present and often dense on at least some branches; fibrils easily break off and leave a slightly raised scar or fibercle on which soralia can develop; soralia punctiform and slightly raised on branches, eroding to form larger soralia in places, also developing on fibercles; isidiomorphs present in soralia. Apothecia sometimes present, terminal, subterminal, or lateral, variable in size, up to 4 mm in diam.; ray fibrils in a single row, variable in number and length; disc yellowish and pruinose; cortical thickness variable, 7–12% of the branch width; medulla dense, occasionally dense/lax, 24–31% of the branch width; axis narrow, 22–32% of the branch width, A/M 0.7–1.2, pigment absent in both the medulla and axis.
Chemistry: Usnic, salazinic, norstictic and galbinic acids, usually all in major quantities (TLC).
Similar taxa
Can be confused with U. rubicunda and U. cornuta. Usually shrubby but can become rangy, it has several branches growing from near the base, the lower branches are inflated, the soralia start of as punctiform but never raised, the soralia produce isidiomorphs and possibly soredia, there are fibrils, the branches taper and are sometimes forked at the tips (but that is often a feature of U. inermis).
Chemically it can be distinguished from U. inermis because U. inermis is never K+. U. cornuta and U. dasaea are both K+ but U. dasaea will slowly turn a deep dark red because of the galbinic acid. Also the axis is very narrow in U. cornuta with a lax medulla.
Substrate
Corticolous
Attribution
Fact sheet prepared by Marley Ford (2 August 2021). Brief description, Distribution, Habitat, Features adapted from Bannister et al. (2020).
References and further reading
Bannister J., Harrold P., and Blanchon D. 2020: Additional lichen records from New Zealand 51. Usnea dasaea Stirt. Australasian Lichenology 86: 114-117.