Xanthoparmelia semiviridis
Common name
Resurrection lichen
Synonyms
Chondropsis semiviridis, Parmeliopsis semiviridis
Family
Parmeliaceae
Flora category
Lichen – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Lichens - Foliose
Current conservation status
2018 | At Risk – Declining | Qualifiers: EF, SO
Brief description
Characterised by its vagant, unattached habit, with no rhizines on the lower surface. When dry, it rolls up into a convex ball up to 30-mm diam. Within minutes of wetting it unrolls, changing into a dichotomously branched, foliose form. In its dry state, large numbers of X. semiviridis thalli often accumulate in windrows, along fences, alongside roadside gravel verges, and among small shrubs, grasses and other debris.
Distribution
South Island: E of the Main Divide. On soil (and freely windblown), in dry inland basins of Marborough (Molesworth), Canterbury (Balmoral, Mackenzie Country) and Central Otago, occasionally close to the coast in the suburbs of Christchurch (in grassland rough on Shirley golf course!), and very recently in alpine scree garden in the Dunedin Botanic Gardens, though the small population developed here has not survived the rapid growth of alpine plantings on the scree.
Also in arid and semi-arid deserts in microphytic soil crusts of SE Australia.
Habitat
Dryland grassland. It occurs on bare, arid soils in lowland (rarely), montane and subalpine grasslands heavily grazed by sheep and/or rabbits, and is often associated with Rumex acetosella and Thymus vulgaris in these depleted habitats.
Detailed description
Thallus unattached, small-foliose, dichotomously branching, dorsiventral when wet, rounded into a ball when dry. Upper surface smooth, yellow-green (usnic acid). Lower surface pale yellow, smooth or wrinkled, lacking any organs of attachment. Apothecia rare, sessile, laminal. Ascospores colourless, simple, 8 per ascus.
Chemistry: Cortex K−, UV−; medulla K+ pale brown, C−, Pd+ orange-red; containing usnic acid, fumarprotocetraric acid, succinprotocetraric acid and protocetraric acid (tr.).
Similar taxa
Xanthoparmelia sorediata grows in the same habitats but is much rarer and more scattered. Xanthoparmelia sorediata is distinguished from X. semiviridis by its deeper, duller colour and the presence of soralia.
Life cycle
In a recent study using a field-based wind tunnel Eldridge & Leys (1999) showed that continual bombardment of X. semiviridis thalli against both the soil surface and physical objects (fallen branches debris etc.) resulted in the breakdown of thalli into small, detached apical fragments that were easily moved by wind. They hypothesise that thallus fragments are likely to move with much higher frequencies than larger, intact thalli, and thereby provide a means of dispersal to new areas.
Threats
Habitat loss and modification of the dryland habitats it occupies. Agricultural intensification (e.g. irrigation, fertilisation) and weed invasion.
Substrate
Vagrant (unattached, on the ground)
Etymology
semiviridis: From the Latin semi- ‘half’ or ‘partially’ and ‘viridis ‘green’
Attribution
Fact sheet prepared by Melissa Hutchison (30 June 2020). Brief description, Distribution, Habitat, Features, Similar Taxa and Life cycle sections copied from Galloway (2007).
References and further reading
Eldridge D.J. and Leys J.F. 1999: Wind dispersal of the vagant lichen Chondropsis semiviridis in semi-arid eastern Australia. Australian Journal of Botany 47: 157–164.
Galloway D.J. 2007: Flora of New Zealand: Lichens, including lichen-forming and lichenicolous fungi. 2nd edition. Lincoln, Manaaki Whenua Press. 2261 pp.