Caloplaca allanii
Common name
Waitakere firedot lichen
Family
Teloschistaceae
Flora category
Lichen – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Lichens - Crustose
Current conservation status
2018 | Threatened – Nationally Critical | Qualifiers: DP, RR, Sp
Brief description
Thallus granular-dispersed or minutely subsquamulose to lacking, in spreading, irregular patches 1–2(–5) cm diam., granules minute, golden yellow to yellow-orange, rounded to sublinear, plane, smooth, often effuse. Orange-brown to brown-yellow apothecial discs with thalline margin of the same colour as thallus.
Distribution
North Island: West Auckland, Waitakere Ranges. At present, C. allanii appears to be endemic to the Waitakere Ranges coastline, as it has only been found from Bethells Beach south to northern Manukau Heads (Paratutai Island). It has a patchy distribution, being apparently absent from much of that coastline. Further field surveys for it on rocks with similar geology elsewhere in Northland have failed to locate it.
Habitat
Caloplaca allanii occupies a very specific habitat, with all collections made from the matrix of the Miocene-aged andesitic Piha conglomerate. Further, the species seems to be confined to the most exposed situations, often growing close to or at the sprayzone. The species also eschews shaded sites. Similarly, at Cutter Rock C. allanii grows some 200 m inland, though again in very exposed situations. Cutter Rock was within the tidal zone at the turn of the century, but following the northward movement of sand, was isolated from the sea by 1954, and now lies surrounded by a dune field. Within its habitats, C. allanii is often locally, though patchily, common. Its normal co-associates include Buellia cranwelliae, Caloplaca acheila, Caloplaca cf. litoralis, Xanthoria ligulata and Xanthoparmelia spp. Of these species it most usually co-associates with Caloplaca cf. litoralis, the other taxa tending to grow on the associated conglomerate clasts rather than the matrix.
Detailed description
Thallus granular-dispersed or minutely subsquamulose to lacking, in spreading, irregular patches 1–2(–5) cm diam., granules minute, golden yellow to yellow-orange, 0.2–0.3 mm diam., rounded to sublinear, plane, smooth, often effuse, K+ reddish purple. Apothecia scattered, solitary to crowded, rounded to contorted through mutual pressure, 0.1–0.6(–1.2) mm diam., disc subconcave to plane, matt, orange to brownish yellow; thalline margin continuous or of scattered granules, concolorous with thallus, present as a thin to thick collar around disc; proper margin thin, persistent, slightly raised, glossy, orange, slightly paler than disc. Epithecium yellow, densely granular, 8–15 μm thick. Hymenium colourless, without oil droplets, 60–80 μm tall. Paraphyses slender, 1.5 μm wide, apices, submoniliform, swollen, to 5 μm diam. Asci clavate or cylindrical-clavate, 55–70 × 12–18 μm, 8-spored. Ascospores biseriate in ascus, oval, (12–)15–17(–18.2) × 6.5–8.2 μm; septum 3–5 μm thick, ¼ to ⅓ length of spore.
Galloway (1985) reported that the spore length was 12–15 μm and the septum was one-quarter the length of the spore, based on the original description (Zahlbruckner & Redinger 1934). However, spore size in Caloplaca can be difficult to determine because spores can be over- or under-developed (U. Søchting, University of Copenhagen, pers. comm. 2012). So for the purposes of obtaining spore measurements for C. allanii, spores were only measured if they were fully formed. Abnormally-shaped spores or those with aberrant septae were excluded. Further, spores were examined from multiple apothecia and collections, and compared with other Caloplaca species in the same localities. The description was subsequently revised to include a larger spore size (12–)15–17(−18.2) × 6.5–8.2 μm; and septum to spore length ratio (one-quarter to one-third the length of the spore) (Galloway 2007), based on the examination of the isotype in CHR (D. Galloway, pers. comm.). Based on an examination of fresh material and the isotype in AK, we have further extended the upper range of the spore size, and found that the smaller spores were often undeveloped.
Chemistry: Thallus K+ purple; containing emodin, parietin, fallacinol, fallacinal, xanthorin and erythroglaucin.
Similar taxa
Similar to Caloplaca achelia and C. rubentior (see Sparkes et al. 2014 for key). Caloplaca allanii can be distinguished from other species of Caloplaca found in the same habitats by its orange-brown to brown-yellow apothecial discs with thalline margin of the same colour as thallus, large spores (12.00–26.25 μm long), with hort septae (one-quarter to one-third the length of the spore).
Substrate
Saxicolous (basalt)
Etymology
allanii: After Dr Harry Howard Barton Allan C.B.E. (1882–1957) one time school teacher, then first director of DSIR Botany Division, and ‘sole’ author of Flora I, the first in the former DSIR Botany Division flora series.
Attribution
Fact sheet prepared by Marley Ford (17 June 2021). Information in the Features and Similar taxa sections copied from Galloway (2007). Brief description, distribution and habitat adapted from Sparkes et al., (2014).
References and further reading
Galloway D.J. 1985: Flora of New Zealand: Lichens. Wellington: PD Hasselberg, Government Printer. 662 pp.
Galloway D.J. 2007: Flora of New Zealand: Lichens, including lichen-forming and lichenicolous fungi. 2nd edition. Lincoln, Manaaki Whenua Press. 2261 pp.
Radio New Zealand 2021: Critter of the Week - Waitakere Firedot Lichen. https://www.rnz.co.nz/national/programmes/afternoons/audio/2018794589/critter-of-the-week-waitakere-firedot-lichen
Sparkes J.H., de Lange, P. J., and Blanchon D. J. 2014: Notes on Caloplaca allanii Zahlbr. (Teloschistaceae), a poorly known West Auckland, North Island, New Zealand endemic. New Zealand Journal of Botany 52(3): 304-309.
Zahlbruckner A. and Redinger K. 1934: Lichenes Rariores Exsiccati. No.s 312–338. Wien.