Caloplaca maculata
Family
Teloschistaceae
Flora category
Lichen – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Lichens - Crustose
Current conservation status
2018 | At Risk – Naturally Uncommon | Qualifiers: DP, RR, Sp
Brief description
Characterised by the saxicolous habit (coastal rocks); the chinky, white, K−, verruculose-papillate, maculate thallus; conspicuous pale-orange apothecial discs (yellow when wet) with persistent, maculate thalline margin concolorous with thallus; hymenium with inspersed oil droplets; medium-sized ascospores 10–13.5 × 5–6.5 μm, with a rather narrow septum, ¼ the length of the spore.
Distribution
South Island: Otago coastline. Chatham Islands.
Habitat
Associating with the saxicolous lichen Dufourea ligulata.
Detailed description
Thallus spreading in irregular, chinky patches, 1–3 cm diam., distinctly areolate, without a noticeable prothallus; areolae angular, 0.5–2 mm diam., separated by deep cracks, surface convex, verruculose-papillate to minutely cerebriform (×10 lens); pale greenish white, distinctly maculate (×10 lens) when wet, grey-white when dry, K−. Apothecia conspicuous, 1–3 per areolae, sessile, rounded to contorted through mutual pressure, (0.2–)0.5–1(–1.5) mm diam., disc plane to convex, matt or glossy, orange when dry, clear-yellow when wet; thalline margin persistent, thin or thick, verrucose-papillate, maculate (×10 lens), concolorous with thallus; proper margin thin, pale-yellow, often obscured. Epithecium yellow, granular, 8.5–13.5 μm thick. Hymenium colourless, inspersed with oil droplets, 60–70 μm tall. Paraphyses slender, 1.5–2 μm thick, apices furcate and swollen, 3.5–5 μm diam. Hypothecium massive, inspersed with oil droplets. Asci clavate, 50–60 × 12–16.5 μm, 8-spored. Ascospores ellipsoidal, apices rounded, (10–)11.5–13.5 × 5–6.5 μm; septum 2–3.2 μm thick, ¼ the length of spore.
Chemistry: Thallus K−, apothecial disc K+ reddish purple; containing parietin.
Threats
Once thought to be a Chatham Islands endemic on the brink of extinction (de Lange 2019), this species has also been found on the east coast of the South Island (de Lange 2012), and additional new populations have recently been found on the Chathams and these “appear to be secure and thriving” (de Lange 2021).
Substrate
Saxicolous (coastal rocks)
Etymology
maculata: From Latin ‘macula’ blotch, meaning blotchy
Attribution
Fact sheet prepared by Marley Ford (16 February 2022). Brief description, Distribution, Habitat, Features, and Similar taxa sections copied from Galloway (2007).
References and further reading
de Lange P.J. 2012: Sole Chatham Islands endemic lichen discovered on south Otago Coastline – Natural Heritage. Chatham Islands, New Zealand. https://chathams.co.nz/ (website accessed: 4
September 2019).
de Lange P.J. 2019: The unexpected near demise of Caloplaca maculata (Teloschistaceae; lichenized mycobiota) from the Chatham Islands. Trilepidea 207: 8-12.
de Lange P.J., Hitchon T., & Patterson E. 2021: New Chatham Islands locations for Caloplaca maculata D.J.Galloway (Teloschistaceae). Trilepidea 207: 3-6.
Galloway D.J. 2007: Flora of New Zealand: Lichens, including lichen-forming and lichenicolous fungi. 2nd edition. Lincoln, Manaaki Whenua Press. 2261 pp.